Valve knows their game best. If a map from the active duty is made by the community, they can't neccesseraly change it the way they like. They can't really benefit from putting community maps in the majors.
I agree with the last part. I'm not satisfied with this operation either, but the maps are the smallest problems if you look at the community. I, personaly liked playing new maps, but as I've said, most people don't, vlave don't have an intention to make us like the maps, so they'll be forgotten in a few weeks anyway