(1) generic (e.g. swerves the thread toward larger/general topic rather than something more specific);
(2) flamey (e.g. provocative on a divisive issue); and
(3) predictable (e.g. has been hashed so many times already that comments will likely fall in a few already-tiresome hash buckets)
- is the bad kind of offtopicness: the kind that brings little new information and eventually lots of nastiness. We're trying for the opposite here—lots of information and little nastiness.