It's hard to know if the Spurs' talent is that bad, because they aren't being put in positions to succeed right now. Again this "see what we have" season only works if the Spurs' coaches actually try to win games. You need a culture that rewards compe ion and improvement rather than just assuming improvement will come if you force-feed minutes.
... I can ream off another anti-Pop rant. I don't feel like doing that right now. In reality, the Spurs haven't turned Pop out as much as some folks are saying. They are passing the ball very well. Folks are constantly pissed that the new guy isn't getting the ball as much as they'd like, but 1) he gets the ball plenty and 2) the Spurs are sharing the ball as much as ever. That type of unselfish culture is a credit to the job the front office and staff have done. They need to figure out the PG rotation, and they could use a smart acquisition of a perimeter penetrator. Their offense is fixable.
Defense is obviously a huge concern, and I do think the Spurs will likely need a new coach and at least a couple of new players to fix that. However, Pop can improve the effort level and cut down on the mental errors if he has a quick hook for bad defense. He doesn't have to yell and scream at a guy. Just pull him aside and let a bench player go in there. That will send both the message that bad defense will get you benched and that good defense will get you playing time. If Pop is teaching good defense and is being ignored, having the hook will definitely change the behavior. If Pop is teaching bad defense, there's no hope for him. The biggest issue will be making sure he doesn't play favors. Pull anyone that makes the mistakes. Do line subs. Don't except your anointed players. You aren't killing them by benching them. They'll be able to come back in a few minutes. If they don't like it, they will have an incentive to not let it happen again. This is when having vets on the roster who can come in and play the right way -- even if they're not good enough to actually make a difference -- is important. It's why you can't just roll with a bunch of 19-year-olds. That was always ing stupid. There's a way to be bad while making progress, and I don't think the Spurs are at that point right now.