Marilyn Manson

Bono. U2 is pretty mediocre to begin with, but with that asshole in front singing Id rather listen to Miley Cyrus.

Foo Fighters used to be real down with the whole AIDS denialism, even financially supporting it.

I know David Grohl is an internet sweetheart, but every time I see anything Foo related, I just immediately wonder how many people died pointless and preventable deaths because they believed the denialism Foo Fighters pushed.

Adolf Hitler.

Rammstein is terrible. Clear cut allegations of systematic exploitation and lawyers who tried to silence big newspapers.

I certainly won’t listen to Gary Glitter’s music

I wouldn't say the horribleness of a person is ever something that makes someone inseparable from their art. The art and the person just don't necessitate each other. That said, I'm pretty sure someone might make a case for Nero, he burnt people on living candles and called it "art" and would lock people in concerts to hear him perform (if we assume the historical records are true). Relatedly, Saddam Hussein wrote a lot of fanfiction about defeating America with negative undertones that would make a Wattpad writer cringe.