Very good points regarding Spurs.
I think another aspect is the fact great teams have players who are extremely good role models and examples of what it takes to be a success in the NBA.
I mean which of these players would be least likely to get on your back if you were slacking. Or set an great example regarding work ethic. See if you've got this skills to spot him in the list.
BARGS !!!!! LOL
I also think a frightening coach helps (Greg, Doc, Phil Jack)