Usually only because it optimizes too much, not too little.
If the point is optimization, then wizards (even assuming spellbook allowed), and VoP, is anything but optimized. You want to have a sub-par character that's out shined by everyone else in the party, that's fine, just don't post it on the optimization board. Min/Max by definition is getting the most out of your character.
But this is really pointless, I think we have answered the original question well enough.