Pop is nearing 70. He's committed, at that age, to coaching USA basketball. He's become very vocal in the press regarding politics. While that might garner him some kudos from the liberal media, a large number of their fanbase is from the other side of the aisle and probably neither side wants to hear about politics while watching basketball.
If you hang around long enough, eventually your ticket gets punched. I hope Pop punches his own ticket before that can happen, but it only takes one incident for the media to turn on him. Let one player say Pop made a racist remark at them. Let something come out about the inner workings of the Spurs that isn't completely PC. Let Becky Hammon make an accusation that one of the staff made a move on her. It doesn't have to be Pop, he would be forced to consider resigning.
I don't see any of this happening, but the more times you pull that trigger, the greater the chance of getting a live round.