It's a community project and some in the community don't want the Affero GPL. Also, it's a fork of a GPLv3'd program where the company attempted to change the license. So, there's already a psychological effect in the community that "changing our license out from under us" is something that concerns them.

I pointed out to the early Kallithea community that perhaps Affero GPL would be a good idea, but they just "wanted the GPLv3 back" after Rhodecode started violating. it's hard to beat that psychological impact.