Yes, that is absolutely true. However, we have to review them first which takes time, and more important game features usually take precident over that. I feel your pain though, I'm getting tired of looking at the same terrains too.
Also, a big problem is that people don't use the bug testers in the editor, or there are other bugs that the editor doesn't currently find.
I can personally do it in two weeks, and even then I think that would be kind of rushing it. I think the idea is to use player created terrains in the main arena eventually, but that is really up to Pyro and HT. There are player created terrains in the CT. Check them out! They are excellent.