The problem I have is, why can't some things be allowed to suck? Why the fanatic devotion to homogeneity? If I want to try the challenge of playing through the game with a non-optimal character, why am I not allowed? Some of my greatest memories of gaming are of times when I was in over my head to a hilarious degree, and somehow managed to pull it off. I just don't see moments like that ever occurring in D3. One of my funnest characters in D2 has always been the flame-thrower sorceress, even though a flame thrower in Hell difficulty is a punching bag. But it's still fun, and isn't that the whole point?
Nobody is stopping you from playing a non-optimal build. They are preventing people who don't want to play a non-optimal build from having wasted all their time. The only way this should piss you off is if you got off more on knowing other people were miserable than on the actual gameplay, which doesn't make it a better game.