Sony is crappy with security but they're pretty good with proprietary hardware. The PCSX2 authors are having problems even with the PS2's VU chip because it's capable of pumping out texture in parallel, and in amounts (not speed) that would make even current videocards struggle if no hacks/shortcuts are used. Thankfully it's only used in rare cases (Final Fantasy XII, for instance, with Basch's mist attack at the end - even in low resolutions, the final part brings a GT 240 to single digit FPS)
I'm a tad confuzzled: do you mean Sony designed it so only they'd know how to use it?
