I watched the Miami-Cleveland game tonight, and something that is glaring about the Spurs is that we don't have a dominant player this year - a guy who can take over a game. Obviously LeBron can, and Wade can, and Melo can, and Bryant can (if he's actually hitting shots).
When we won championships, Tim dominated games, and our defense closed them. It was that simple. This year, tim is playing well, but he's not as dominant as he was. That's fine, we all know who he is at this stage. But our defense is not even Spurs defense. Those days are over. Manu is not taking over games anymore, and Parker isn't either. Parker is slowed by the PF. Manu is still inconsistent, and even when he's really on, it's only for short stretches.
For the last three years, Pop and the FO have been expecting the 2007 Spurs to just spring to life, and now guys are three years older, Manu blew two straight playoffs with injuries, and we find ourselves where we are now...smack dab in the middle of mediocrity.