It's simple, really. A character's past is what -you- make it, not what the game makes it.
But earlier games allowed me to simulate my character's past. That's the difference. If I wanted to learn other things, I could... I didn't have to. But it would take me longer to increase those skills. Until I did become formidable with them, I relied on my major skills to survive. But with level-scaling, there's no point... which is another flaw.
Also, why must my character, who can obviously live forever, be limited in number of perks? Who says I can't master everything if I spend enough time doing it all? It only makes sense. Practice makes perfect... unless you have already reached the limit of perfection that the programmers put on you.