You can "rah rah" about exclusivity all day long. What needs to be acknowledged is how huge this is in terms of developers under one company. As far as I can think of, there's never been anything like it. I don't think it's gonna be for the better, I mean this is the same company responsible for this
GFWL was one of the worst attempts to compete with Steam I've ever seen, and also one of the worst software experiences I've ever had. I never got more than an hour into GTA4 because of it and how intolerant of bullshit software I am. Valve should have put their feet down back then and said "no secondary launcher dependencies".
Game pass is OK in terms of value if you play lots of games, but the software it uses is not great, despite being leagues better than GFWL. Windows also sucks, but I'm stuck with it due to work :/