Your question was does it make sense to judge their art in isolation from the artist. I'm saying you can in fact do that and as an exercise in proving this fact

Your question was does it make sense to judge their art in isolation from the artist. I'm saying you can in fact do that and as an exercise in proving this fact I front load the art and follow with the artist and the net effect is positivity rather than hostility. But even if you were to present a monster's art in tandem with the fact that the artist was a monster I would go even further to bet that most people would judge the art on its own merits and find its origin trivial, even ironically humorous. I've known very few people who pearl clutch in life the way they do on the internet.