I think that it's people who haven't played organized, coached basketball, and learned the game, that don't appreciate the Spurs. Unfortunately this is a lot of people.
For example, I never played football, but I've sat and watched with people who have. They see, literally, 20 times more things than I do in a given play. They appreciate spacing, blocking, fakes, how the snap count is done, and all kinds of stuff like that.
This makes me understand what it's like for someone who never played except for pickup games maybe feels watching the NBA. There is so much going on that they do not even see, much less appreciate.
For example, one of the things I absolutely love about the Spurs is their defense in the paint. You saw that over and over again in the second half of the last game against Denver. Someone would drive the lane and the Spurs would converge on him and pressure the shot and the drive enough so that they'd miss 3 out of 4 times. It's not about spectacular blocks, it's about just bothering them enough to get their percentage down. Whenever I see that I just grin stupidly. I'm sure others watching say, "Wow, that player missed an easy layup." Or, worse, "Wow, the refs sure missed that foul."