If you were to boycott works of art based on objection to the moral compass of their creator, you wouldn't have a lot of art left in the world you could support. Picasso was a pretty awful human being, but I can still dig his paintings without feeling like I'm supporting egotism, chauvinism, adultery, and Stalinism.
Likewise, I'm not going to boycott the MTA and not ride the subway because they commissioned sculptures from Tom Otterness, a sculptor who, thirty years ago, bought a dog and filmed himself shooting it to death as an art project.
I generally do believe in the concept of voting with your dollar, but I think this is different than not buying factory farm meat, sweatshop-made clothes, or whatever. Video games are highly collaborative projects. That one person among the group of creators is an awful human being is no surprise and should not color the finished product. I think it's a stretch to say that buying DQ games supports revisionist history.