I've always felt like, since I started using Steam, that Valve tried to stay mostly neutral in the process of selling games. Greenlight came along and it was like "Well that was a train wreck but I appreciate the gesture to new developers, despite the obvious profit motivation for you." Different things they have done with a business motivation (game sharing, Steam Sale games, etc..) I've always felt like have hit a 50/50 balance of fairness to the consumer and profit for them.
This is the first thing they've done since I started using the service where I feel like the balance is out of whack. Maybe 25% of my feels goes towards "Yeah, rewarding content creators!" The other 75% though is in: giving the lion's share to either themselves or the game owners and willfully sticking their hands into the modding community with the offer of money and changing the dynamic. That's not Neutral.
It's said that as the lifespan of an organization continues, whatever its initial reasons for being, its goals eventually become perpetuating its own existence. And this sort of feels like a means to that end. Valve makes more money and the companies who previously didn't get to make a dime off of player created content are now making an unknown but potentially majority share of. In six months, all the major content providers are going to start investing effort in controlling the modding scene in some way, trying to make a profit from them. When Valve succeeds at something, other people follow suite. This all feels very far removed from something like Greenlight which allowed new things to happen. Paying Modders is really only about making someone money. Which was pretty much unthinkable in the modding scene until now, not just because of the legal issues but because of the principle of the hobby. Person makes a change to a game and shares that change with the community.