Because this is likely to drive a lot of people to try switching. And they're the type of people who try to convince other people to switch, too. Techies, etc.
When forced with trying to keep family safe from abusive and/or manipulative ads, this is a pretty hot topic. Plenty of people tell their family what browser to use and even set it up for them with ad blockers, etc.
I've recently had some experiences that tell me my parents are at a vulnerable age and can't fully protect themselves, so it's pretty important to have control of this.
They've been quietly preventing Firefox from becoming a threat for a long time. There are constant little things that just mysteriously don't work as well on Firefox, for no reason. People have changed the user agent and found that it works just like on Chrome with Chrome's agent. Youtube was doing it for a while, and reviews on the search are another instance. I was at the Dentist's and they were asking for a Google review, but I couldn't find the spot to leave it. I switched to Chrome and it was magically right where it was supposed to be.
So they already think Firefox could be a threat, and preventing ad-block is going to make it a bigger threat.
Its not google services i worry about ive pretty much degoogled everything i can. Its the google bits so deeply embedded into almost every website across the internet. If they implemented some tpm bs into chrome that somehow Verity's itself with tpm and google servers before it loads anything then that instantly makes a majority of websites juat not work on ff with no fixes backdoors or bypasses. They will try, we have little hope in stopping it, and most people wont even notice let alone give a fuck.