I can tell you why I stopped jumping.
1. The community is crap.
2. New maps aren't that interesting. The focus has become new ways to exploit the engine (power bounces, edge slides, normal bounces, edge bugs, etc etc).
Not much can be done about #1 and that's really just personal opinion anyways. But if interesting maps were put out that didn't rely on gimmicky shit I don't care about, I'd still be jumping a lot more.
Do more collab maps. Take submissions, and have one or two people be the final editors, like how jump_christmas was made.