My experiences with 4e have taught me that most of the design for PnP RPGs is blatantly archaic and the players are too blind to realize it. Case in point is a particularly stupid houserule that I experienced in my 4e game. Critical failures. No matter whatever you do, you have a 5% chance of flailing about like a complete idiot. It's archaic, it's stupid, yet a number of PnP players seem to love it. And what's worse is that numerous PnP games have nonsense like that in their core rules. Even if it's just toned down to "you're not flailing like an idiot, but you are useless right now, so go get a soda and watch some TV."
Makes me appreciate the structured design of 4e all the more. Where they're not just tacking on every little silly rule they can get a hold of.