I didnt quit CF cold turkey. It was casual loss of interest, then quitting all together for months at a time. After not playing for nearly a year I came back to give it a try, and quit after a couple short lived characters. CF would have to change so dramatically it wouldn't even be CF anymore for me to start playing again. It would be a game where there were no level grinding, no huge time investment into area/prep knowledge to compete, and just all around more fun and less time sinks and frustrations. RP = fun, PK = fun, Exploring = fun. Exp penalties = Suck, Sucking at CF = sucks, Sucking at PK = sucks, Killing a hundred thousand mobs for the 50th time to level a character = sucks.
Dwarf fortress is a game that I still have fun losing at. CF sucks to lose mainly because of time investments. Prepping, gearing, EXPing, etc. I don't want to change CF that drastically, I just don't want to play it anymore either.