The problem is that the OTHER Homonculi seem able to choose some course of interpretation. Greed decides he LIKES humanity and ends up choosing to work with someone who'll give him BOTH the opportunity to be a hero AND get all the good stuff too. Wrath looks like he's somewhat conflicted on the real direction he wants to go. Envy COULD have chosen to take the "overcompensation" path of Envy instead of the destructive path. Instead, he's a whiner.

Yes, I detest Emosuke. Gaara shows the path that people like that SHOULD take. Start out a total dick and sociopath because you're rejected and have Evil sealed in you, THEN change when someone shows you it doesn't have to be like that.