User blog comment:GVASS/Chapter 52 Predictions? Possibility of a Time-skip?/@comment-24121336-20131109075043/@comment-179280-20131109081757

The manga is monthly because that's how the magazine releases. You cannot change that, and you should know that Isayama applied for a weekly magazine at first, but was rejected because the story wasn't riddled with clichés.

Besides, drawing all that stuff by himself takes him like 3 weeks, and I think it's much better if he works alone than with a team (which may lead to creative conflicts and such). I could care less if anime-only fans cannot endure the monthly schedule.