I can't speak for everyone else, but my stance is that the player shouldn't have to handicap themselves to balance the game. New Vegas as it is, is hardly a challenge at level 30, it's no challenge at all at level 40, and this is to say nothing of level 50.
New Vegas is an RPG, becoming a wasteland god shouldn't be an option at all. Each different player character should have strengths and weaknesses, and if it's possible to become a jack of all trades then you may as well have made the game a first person shooter from the start. Giving an optional perk that caps the player at level 30 is hardly consolation. We shouldn't need that perk in the first place.
This is how I feel as well.
You see, the whole point of balancing a game is to insure that player characters cannot just stomp all over everything once they reach a certain level. While a L30 or L35 character is already quite powerful, there are still foes than can, and will, kill you if you're not careful; a L50 character, on the other hand, has so much more at his or her disposal that said formerly difficult combat mostly becomes a joke. That the DLCs keep introducing powerful equipment only the player has access to does not help, since this just widens the gap between player and NPCs.
There's also the perk issue to consider. At the current level cap of 40, one gets 20 perk picks; by this point you are probably starting to pick perks for a second weapon skill, since you already have what you need for your primary one, while with the old cap of 30 you got 15 picks and would have to give up pretty much all non-combat choices to get more than one weapon skill's perks in. The addition of even more perks from 441-50 means that you'll be able to master pretty much everything at once, which kills character diversity and removes the 'Role' part of
Role Playing Game.
Now, if there was a way to rebalance the creatures/NPCs such that they would still be a challenge for a L50 player while not turning them into walls of HP then we wouldn't be so upset, since there would be an actual reason to get to such a high level. As things are, though, the only reason to do so is to become a 'master of everything', and that gets old,
quickly, at least for us.