Valve aren't looking to make money here (well, obviously they are, but not directly from this like you are implying). $5k a game means literally nothing to them - the amount they make from sales makes that a joke.
This is a matter of competing pressures. We want indies to be able to publish as easily as possible, but customers don't want to see lots of bad games.
The easier you make it for indies, the easier you make it for people pushing out crap. This is clearly a response to people's complaints about the lowering quality of the average content in the Steam store, after their attempts at providing better game discovery methods and curation systems haven't solved the issue.
This is a matter of competing pressures. We want indies to be able to publish as easily as possible, but customers don't want to see lots of bad games.
The easier you make it for indies, the easier you make it for people pushing out crap. This is clearly a response to people's complaints about the lowering quality of the average content in the Steam store, after their attempts at providing better game discovery methods and curation systems haven't solved the issue.