Whomever wrote that the problem was that the level and skill tree system pushes you into levelling secondary skills had it almost right.
In my view, the problem is levelling all on it's own. It doesn't really matter what skills you choose to level with, if you want to level, you have to pick a variety of skills. For most, this will naturally involve picking a combat skill and crafting of some type. Without doing research on which perks *not* to pick, it's very difficult to both level and not create something that's overpowered by level 25
If I wanted to play a straight up dual-wield warrior, I would be levelling only 1h and my armor skill. Through natural use, I might get a few skillups in Speech and Lockpicking. Doing it this way limits my character to ~20 levels before I max my chosen skills and simply stop levelling. I am also nowhere near having enough perks to fill in both the 1h and armor trees. If I want to level more (and I do - the desire to level is ingrained in everyone these days) I will naturally choose skills that seem to be somewhat related to the theme of my character - crafting. You don't need to go very far down the crafting path before the game difficulty really starts to suffer. The same thing happens no matter which combat direction you choose.
Now, if you choose to not level - at all - and play as a level 1 on master, the game is incredibly difficult without power-levelling skills (and even quite hard with them levelled). Forgo all the levels, and the game is always challenging.
So the choice appears to be:
1. Level naturally and create an overpowered monster.
2. Research how not to play, and build a balanced character.
3. Don't level at all and force challenge.
That was me who wrote that and I would like to comment on what you said here. See I am an experienced fallout and TES fan. Played them all... Iv'e stuggled, Iv'e balanced, and Iv'e broken them all. But I've never actually made an OP character, honestly, never happened once. I also wasn't on forums back then, or looking to be OP. But it happened in skyrim and it's the first time I'm on a forum cause of it...
Here's my experience: I jumped in and looked at all the skills. Broke it down to how many perks "I MUST HAVE" to the number of what I would like to have.. The number of perks was like 54-69 or something(For my specific paladin style build). Right away I looked online to find out max level to see its mathimatically calculated to be around 77-81 maxing ALL skills to 100. So I thought crap, I'm going to need to max roughly 15 / 18 skills to get what I want. Dear lord I thought! This seems harder than oblivion but ok here goes.
I start as a warrior roaming caves etc... Next day I played under the mark of the thief and joined the thieves guild. Then went back to warrior cave diving and questing. Hoping back and forth I was naturally leveling faster, and I needed to in order to even experience a boss fight with a end game perk. I didn't like the though of fininshing the game before my potential last perk which offers a pretty cool mechanic. IF anything, I want to practice these end perks in combat and play with alot of them before retiring, or even coming close. From the looks of things. A "normal" playthrough is stale and lacks any end game perks or variety and theres still a feeling of, I havn't really explored much of these 18 trees, at all....
So I ended up finding the lovers stone 15% to all skills rather than 20% to say just warrior. Much better for general leveling. And as I played I would take advantage of situation that offer skill ups. after I hit level 35 or so, I pretty much found it really hard to skill up and went to some old oblivion macro ways. Such things as spamming courage on my follower for 10 minutes to max out illusion. The really easy to do stuff! Summon an atronoch and crank on it with a mace on the hardest difficulty while healing yourself. That sorta thing. Ok, you may argrue that i'm not playing the game "normally", but playing the game normally will eventaully lead you to the same result, but you could potentially finish the game before that, resulting in nothing at all... What's worse>?? If im investing 100+ hours, I better have shield charge and damn well love it!!
Soo here I am now, level 69, most skills are at 100, some are in progress, (waiting on making a mage set for some skills) speech, lockpick, pickpocketing skills sort of need to be level'd as you go.... I have a few maxed out trees, Block, 1 hander (mace spec), heavy armor, enchanting, the heavy side of blacksmithing, most of restoration, half of speech, 3 into pickpocketing (carry weight perk) and basically my last points will be fueled into alteration to finalize my ability to buff and have magic resistance. These are all thing I must have to even feel remotely close to any sort of paladin i was able to create in the past Elder scrolls series. So after about 3 days playing I had my plan and KNEW i needed about 64 perks to feel fofilled as a paladin. In oblivion I wouldn't have to "macro" skills to get this powerful. infact this is just a common paladin build. nothing crazy. I picked roughly 7, and oblivion those 7 would get me to level 70 playing normally. So the ISSUE is that, I have to macro to get the same style character I love playing in these games. Im forced to get a higher level, in order to experience things a lower level character would get in the other games. Therefor, as a human, I cannot backtrack in gameplay. I expect equal or more power than I had in the previous games. And in order to get there, I had to hit about level 50 before I really actually fealt like a paladin (in oblivion it happened at a much lower level). In oblivion I macroed to get all skills to 100... But didn't recieve any bonus's at all for doing so (after your 7 majors are up, your max level).. IIn skyrim I max all abilities to achieve a regular character in oblivion, which is considered OP here.....
They basically made the characters 3 times less expansive... I cannot express it enough. Read all my previous posts (if you can handle it!), I make very valid points.
BESIDES the point.... I will be hitting 80, and will be happy with my 4 maxed trees and 4 other half trees... I will be happy with my overal character, but I had to go out of my way to play three classes to achieve a master in one class.. That's a bit anoying, especailly when I want to master a new class. My whole anology is: in skyrim you must play all three classes, three times each, in order to experience the game once with each class. HAHA! It does make sence in a wierd broken system kinda way

But ya, the factor of this whole topic though, is OP'ness and brokeness etc... Well, even at 69 I die on Master time to time. Pesky mages and things that shout can be a bother. But soon with maxing alteration and enchanting, my resistance will make the game "normal". My character doesn't become OP persay, (im not doing the 3 craft skills cheat either) . But it's really not that hard. I was actually flipping it from Adept to Master from about lvl 30-60 now I just leave it on and deal with the tough situations like it's a rare goldmine.
So I have many rants and posts adding ot what people say or debating opinions. In the end I enjoy TES series, lore, stories, and characters, and defining my roll that I want to play. Skyrim overal, I have 1 of 3 choices to define, and I have to play all 3 to define the one choice. So in otherwords, were all doing the same exact shiat to get to 80... Exactly... And if your smart, you DONT waste your time, and DONT play normally, cause playing normally you never end up finishing with 8 perk trees glowing... But if you do get all 6-8 glowing skill trees, 8 / 10 times the game is REALY "easy". If I was a 80 mage I would be perfectly happy right now with the challange of the game on master difficulty. Only problem is I am having problems wanting to play a mage after reading all this about the crapy mages and no spell crafting. Not to mention 6 less keybindings for xbox (leaving us with 2 now), so it becomes dubachary trying to swap magic skills.. Plus I play arcane warriors, monks, druids, shamans, all the things you can't play in TES anymore....
All in all, ya the difficulty needs to be bumped up so that there is no such thing as OP, and those who are curious can find out that INSANE mode actually looks impossible. Maybe the crafting cheat will become viable on this mode, and still be tough!.. Really, that's not alot to ask, but I gotto rebuy the game on PC to add that myself. And my list of game breaking bugs on my previous posts pretty much just tops of the reason I 'm here whining about balance in the first place lol.. My games slowly becoming unplayable, as I cannot enter or leave my houses anymore. and quest NPC's are totally forgetting about important quests they gave me... At first I wasn't going to wine about the game getting easy later on. But after I lost ability to use my house in riften, and can't become Thane due to bugs. Re-rolling and "hoping" to Re-avoid these game breaking bugs, while knowing the game is going ot be super easy later, just doesn't seem worth it. So now I wine like a baby and hope someone patches my current game, or allows my next one to be a bit more challanging to make up for lost content......