Ya, it would be super helpful in rating integrations to take into account vendors that don’t play nice with HA, as well as document which vendors are open-source friendly and which or not.
The question is why should they? Why not continue with enshitification which can provide more revenue. Start charging for basic features and put more ads 
The forced arbitration was already acknowledged by all customers so they even lost the right to sue 
The only vote possible is to avoid this companies 100% and vote with your wallet. Obviously let them know and help others making poor choices by warning them about this shitty manufactures which are getting more and more… 
It’s a shotgun approach at minimizing their risk, but it’s not zero. I am in Ontario and I am protected against forced arbitration by my province. It depends where you live as to what protections your government provides you as a consumer.
As to why a company might want to stop - entirely reputation. They may still have their die-hard fans… but the others will walk away and it can have a significant impact (just look at Tesla). Rarely just a single owner in larger companies like this, which means that the top brass can get canned if they ruin the rep bad enough.
Be real, do you think that even 1% of the users buying cloud/app/account based products without real ownership and no or limited local control do care at all?
Not even the majority of HA users really care about privacy, sustainability or local control
You really think this got anything to do with (technical) enshittification and not because of the controversial behavior of the CEO? 
vs 
No idea, and I’m sure that in most cases, new customers make up for lost ones when companies do stupid stuff. There’s no end to greedy companies, ones that just don’t care, etc… The best we consumers can do is tell them and others how much they pissed us off and hope that our voice convinces others to do business elsewhere.
I’m not looking to change the world, just help others avoid making the same mistakes I may have made.