I know those early defectors messed him up, but Coach K is lucky he's highly respected, a coaching legend, and white. If he didn't have all three...his job would be in jeopardy in the near future. See Kentucky for reference.
You don't fuck with the dude that built your program. He gets to go out on his own terms as long as he does so in an honorable fashion. There's a reason Bobby Bowden and Joe Paterno haven't been fired. You don't fuck with the architect.
Kentucky is an arrogant machine that doesn't understand it's past it's prime. While I think Gillespie has done a terrible job, I think he deserves another year.