Morally acceptable to whom? To society, or to me? I think we demonize each other too much. There are people who do things that are destructive to others, but there are no "bad people." We all spring from the same source, and what makes someone "bad" is only a long timeline comprising a feedback loop between decisions/reactions and experiences, a timeline which a third person isn't privy to and can't understand. That's why they say not to judge someone until you've walked a mile in their shoes. And starving someone of attention, love, money, happiness, or whatever won't help them or make them a "better" person. If anything it'll have the opposite effect. One of the major changes humanity has to make in order to survive and prosper is to embrace each other. And anyway, just "liking" art by a "bad person" won't make you a bad person and it won't further proliferate whatever injustices the "bad person" commits. And a morally bankrupt person can easily produce good art. It's not all black and white, everyone, even Hitler, has beauty to them.