Why is the Marquis de Sade considered to have literary value?

[FreethinkingSceptic]

Basically, he was an advocate of rape, murder, sexual torture, and general perversion. Some apparently consider him to be of literary or philosophical value, but I see him as just a sexual deviant and a monster. Basically just a role model for serial killers, rapists, and pedophiles. Does anyone want to make a case for him having literary value?

[Unbeliever]

I was unaware that he had any literary or philosophical value.

[Mr.Obvious]

I have not read any of his books. So i can't judge.

But let's modernize this question.

If any of  the horrible accusations of michael jackson are true, and i personally believe some of them are though i cannot prove them and i will freely admit to that, would MJ's music have any value?