In my opinion Steam has done a lot of great things for PC. But for me personally it hasn't done a lot. I've bought one game from Steam in 5 years. I built a pc to game in 2011. But after quitting Star Wars The Old Republic, i haven't really felt anything that has kept me gaming in PC. A lot of the games on Steam are shovelware in my opinion. The sales are also overrated as there isn't a lot of games that appeal to me during the sales that i haven't got already.
The biggest issue i have with Steam is the quality control. There is barely any of it. Now don't get me wrong, there are glitchy and half assed games on the consoles aswell. But in my opinion there are way more broken games on Steam than there are on any console. When Steam let's games like War Z, Air Control, Earth: Year 2066, etc. Those type of games do not make it to the consoles and it's becoming bad.
Even though i hate EA as a publisher, i like Origin more than i do Steam. Because i know what games i get( yeah, yeah Battlefield 4 was broken as hell). But you get my point. Steam has too much broken games for someone like me. That's a reason i switched to consoles entirely a few years ago after playing mostly on pc.