You're not a horrible person unless you're that one guy who blames others for your mistakes. Everyone has their own preferences, nothing wrong with that. Plus if you pump out optimal damage on you chosen job; you'll be valued highly.

Personally I enjoy all roles (mainly AST/WHM, but if I don't feel like healing I'll go PLD, MNK, or BRD, [also DRK on my alt]). I like utility, and I like being able to fill roles that are needed. I'm a red mage at heart, jack of all trades :P