Earlier quoted context omitted.
AOSP is so open that the previous AOSP leader at Google quitted over the lack of openeness.
That's a mischaracterization of his own comments on why he left. It had to do with open sourcing GPU drivers, which is probably an issue with other vendors, not Google. See: https://plus.google.com/112218872649456413744/posts/9HHRURor...
Your argument itself is also somewhat of a mischaracterization, because at least Google could have wrestled redistribution rights for the binary drivers, thus making AOSP actually usable on the nexus, and they didn't even bother with that.
Vendors are a convenient whipping boy when don't care about openness but wanna look like you do.