His post isn't for you.
It was written on his personal blog, announcing to the community of people who look up to him (and yes, there's a community) why he won't be in the places they expect.
Adam was a UX Engineer who saw a job that needed doing, but didn't exist, so he willed it into existence. He found a way to use his talents to literally make the world a better place. (I don't care if you think there are more important jobs - the truth is that the internet mediates most of our societal interactions, and he was making it better for everyone.)
He was doing a kickass job at it too. He should be hurt and angry to have that rug unceremoniously pulled out from under him.
He doesn't need to pay lip service to starving kids in $REMOTE_AND_DESTITUTE_PLACE or self-flagellatingly privilege check. His blog isn't here for your entertainment, and he doesn't need your approval.
There aren't many companies that have such a symbiotic relationship with the web platform to be willing to fund people to make the web a better place. For a while, Google was the foremost place that did.
Adam is immensely talented and a wonderful person on top of it. Hopefully a great opportunity will snatch him up quickly. But there aren't many places to do the work he was doing. He deserves to be mad to see the job he worked so hard to build swept away by some antisocial business school bullshit. And as the people who will miss out when he's not there to make the web a better place, we do too.