Also, don't assume that all players are spending all of their available time already. BM is pretty slow-moving game by design, and the amount of time people spend trolling these discussion boards is evidence that some people have extra capacity.
This is correct. I have the time and inclination to write one or two roleplays a day, but as it is there simply isn't enough stuff going on in game for me to base them around. As a result, I tend to only write a single roleplay every few days.
Excess roleplay time goes toward pointless forum posting.