All along Google has behaved in a way inconsistent with their "Open" marketing. And people have criticized them, not for what they were doing, but for trying to contort the definition of "Open" to still fit what they were doing.
Now that the project doesn't even meet the most-basic definition[1], there is simply no more wiggle room and those who would prefer "Open" still mean something at the end of the day are again pointing out the Emperor is naked [2].
[1] As codified in Rubin's famous tweet.
[2] Not because it's wrong to be naked, but because he insisted he was wearing clothes that he quite clearly is not.
Throwing a source dump over the wall to out of date code has always been their operating procedure, but they've never publicly stated, as bald-faced as they have now, that they're not going to be releasing the source because they don't want smaller ODMs to have access to it.
This has nothing to do with hobbyist devs, this has everything to do with keeping Honeycomb limited to the few companies that have paid Google hundreds of thousands, if not millions of dollars for that access.
The rest of the manufacturers aren't "worthy".
If Google had said "We're not as secretive as Apple", there would be less bitterness now, but there also never would have been the sort of momentum/buzz they built early on.