I know a few who have left or are thinking of leaving.. Mostly it is the time involved.. Most of the time in this hobby you don't throw a plane together in 1 night and go out and fly it at aany random point.. Yet you have to spend hours building then wait for the right weather to fly in. So left for their family, which I agree is not a bad reason, and others have left for careers, again not a bad reason.. I don't see boredom as being a huge reason to quit this hobby, since there's always something new coming out, and always some new manuever being invented or a newer bigger fly-in to be at.