I have yet to experiance burnout with tabletop but that has more to do with my relative newness to the hobby. Being a shy child made getting a group together to play with near impossible (Glad that's all over). However, one of the people I've found to play with has told a few stories of it. The way he talks it gets pretty bad and can end up ruining friendships when handled poorly.

The best comparison I can make is putting down an MMO. Runescape, WoW, Guild Wars, lots of time dumped into them. Haven't touched any of them in years because of the burnout. Stayed out of guilds for the most part so I could fade off without ruining anyone else's plans. Realizing that this happens to me a lot has ruined my enjoyment of the genre for better or worse. I miss them a bit but none of it really mattered. The rules you layout for avoiding and dealing with it are well thought out and helpful. It makes it a little clearer why you started making your own system.