Why can't other manufacturers do the same?

I know SONY does this, but its only after some sort of "consideration" period. Then they go all-out and include it in their AOSP-project tree.

HTC is like "yeah, we'll get on to it..!" then whispers "when we get onto it" smirks.

LG is like "what you want!"

Samsung is like "Okay how about a leak instead?"

They're all horrid. Except for Moto who is good and SONY who is okay.
I wonder if Nokia would've been this bad/better considering the proprietary blobs in the open N900 and the Aegis debacle in the open N9.