Actually, I think there is some wisdom in doing just that. Designers flub things from time to time, and in others they just can't tailor stuff to our home-grown campaign.
Rather than moan and wait for designers to fix everything (or worse, choose our game style for us), I think the DM ( and sometimes the players), should step up and do what's right for their game. If that means brewing up your own content, stealing it from elsewhere or mixing up the rules to fit a certain gaming style, I'm all for it. As long as everyone agrees to it, what's wrong with cutstomizing your game the way you want it to be?
This is a game of imagination, after all - nobody ought to be punished when they use it - fairly, that is.