Well, you've answered your own question there, but that's still not really DRM. Publishers abandoned the PSP en masse due to how easy piracy was. Sony are already having enough trouble getting them to release games on the Vita, no way in hell any of them would touch the console with a bargepole if it wasn't locked down to some degree. That's just common sense. You can't play copies on any other modern console out of the box either. Except for the early Dreamcast consoles of course, which wasn't intentional and again resulted in most third party publishers jumping ship after the first year. Even so, casual piracy was a hell of lot harder 15 years ago than it is now. CD burners were still expensive and it was a nightmare trying to download anything that size on dialup internet. That alone made it more trouble than it was worth for most people.
Memory cards being linked to your account because of digital purchases is unavoidable nowadays - other modern consoles do the same thing (underneath the surface they're actually locked down even tighter) but you don't notice because you're not taking the hard drive out.
Bottom line is there's no region lock on the console and nothing preventing you from buying physical games and treating it like a DS, PS2 or any other console if that's how you wish to use it. The only way you're restricted is in regard to digital games, which you've said many a time you have no interest in anyway, so it's a moot point.
