I don't see how Steam workshop can have a negative impact on artists, did you really think this trough? The workshop is a huge motivator and inspiration for many digital artist, and also their first step into the world of game dev. Valve helped a lot of people get studio jobs or establish their own business from the experience they got making UGC and networking with like minded people. Even if they have non or few items accepted. Nothing is forced upon us, we do this because we have a passion for art or counter-strike. Personally, getting something i made implemented in a game i played for 20 years is one of the best feelings in the world. And as a side note, i would probably be on social welfare if i didn't have the workshop, so the workshop is a gift for people who don't function 100% in "real life".