Art is in the eye of the beholder.
A question, though: If you found a painting to be beautiful and loved it, but later found out that the artist was high when he painted it, would you not find it beautiful anymore or not love it?
(Also because I think the distinction matters. Sports involves competition. Not all art does. If a person enters an art contest and is using drugs to make their artwork better, I would consider that cheating. If they're just doing something for fun? It's other things, but not cheating.)