The problem with Character for AI is that it has potentially much more capability to affect others, and same as with people in power society disagrees what kind of person, with which culture and views should have it.

Impeccable game theory character will sacrifice millions to save billions, everyone must agree to give such choice to a machine, and at the same time they have to trust the characters of people who creates that machine. Otherwise it boils down to some group of people deciding what is good for everyone else.