It's not about 'inferiority problems', it's that willfully taking an obviously inferior path never feels good. You might love Druids or dwarven fighters to the point that you will take them even if they are weak (i am that way with druids), but that doesn't mean that it's not annoying to willfully making your character weak.
Especially if you like overcoming challenges. In that case, if you can beat the game with a weak char in the hardest difficulty, you'll feel something is wrong with the game, and if you can't, well, you may feel you need to use a stronger char.
He didn't say the build was weak, he just said it wasn't the most optimal. Big difference between a build that can't complete the game and a build struggling more than another. Sad to say, there will always be 1 build that is "the best" wether it's by a foot or a mile. The worst part is that developers tend to nerf rather than buff the weak.