Rok, it seems you have the most complete list of reasons for not being on the list of greats. I seem to know many of them personally; some even had beautiful wives they didn't want out of their sight for too long, or was that a tennis player who retired after he reached the top, decided to come back in, and didn't make it.
After thinking about all of those, would have, should have, could have people; I have a lot more respect for guys like Donald Byrd who changed style so many times, and survived at the the top for the duration of his life.
Enjoy the music.