I agree, MemoryScenes. In fact, I've always found Portnoy's attitude toward his instrument to be at odds with Myung, who is practicing every time you see him, James, who's done wonders to his voice in recent years and Petrucci and Rudess, who are constantly trying to one-up themselves (and eachother). In sum, I doubt there's much more to Portnoy's attitude than the image he wants to display.
Lately, I've looked at it this way: circa 1998-2003, Mike Portnoy was THE drummer that drummers were talking about. Just listen to his work on FII or Scenes, or the first 2 Transatlantic CDs; In almost every song, you can hear how badly he wanted to keep those drummer awards coming. Around 2005, though, things really started to change. Portnoy was no longer as "in" as much newer guys like Gavin Harrison. I think, judging by some comments made on his own forums and other drum forums around that time that maybe he wasn't really thrilled with the shift in focus away from him.
That's where Portnoy the "reclusive" drum god steps in. Having had his day in the sun, Portnoy's accepted that there's people on the field now who, quite frankly, can play anything he can play with 1.) a smaller kit and 2.) their eyes closed. Instead of pushing himself to surpass these people, he's dropped out of the competition. That's where stuff like "Eh, I don't really care about my gear," and "I almost never practice" comes in. I'm sure he still practices, but he's not "competing" anymore.
In fact, Portnoy likely always practices. He's constantly touring and playing in the studio. Some of his drumming on Nightmare is way different than what we've ever heard him do before. We have videos of him on Youtube opening up "new gear," talking about gear, and practicing with his son.
But he's simply not competing anymore. He's not overplaying. You can tell by listening that he doesn't care if his performance gets him a "best drummer" award from a magazine anymore. That's the important distinction we need to make.