Reports at the time of the trade were that CP3 to the Rockets was a forgone conclusion and that the Spurs never had a chance of getting him. Doesn't sound like PATFO did their diligence and we got Pau's awful contract as a result.
Your question was: is Pop doing a good job. Giving out those contracts is part of his job. As is managing the relationship with his A#1 player. I don't know why you don't give a about reported tension with Kawhi - that's the one player who you can't afford to lose.
I'm happy to give him credit for things he's done well, i.e., LMA. But to me that's far outweighed by the ups. My point is that you're giving way too much credit to meaningless records like 50 wins and seeing the writing on the wall. He's been at the helm for 20+ years. It's only natural that he'd eventually fall off.