The main issue with PbP tabletop is that it gets bogged down quite quickly depending on the group. Unlike regular freeform RPs, tabletop RPs rely on dice, and even something as simple as combat can crawl to a halt because you're waiting for someone next in the turn order.

Also: Fantasy is one of the more popular genres on the guild, so it isn't so much a lack of fantasy RPs. The guild has been in a bit of a lull for awhile by now.