They paid antirez and I'm sure compensated him for his efforts on redis. I haven't heard antirez being "kicked out". There may have been a separation of ways when redis inc. decided to not be truly open source, but I haven't heard of them being abusive or unethical with antirez.

So yes, antirez started it. He owned the trademark and gave it off to redis inc. and was compensated for it. I am not seeing why this has to be controversial.

I don't like what redis is doing. But they're within legal rights.

Yes, nobody says that there's something illegal here. Were it so, Redis is high enough profile project for someone to take a legal action.

But this is a takeover that is slowly draining the value from the community and directing it to private pockets. E.g. Redis is now source-available.

There are still compatible alternatives: https://valkey.io/ (C, a direct Redis fork) or https://keydb.dev/ (C++, an evolved Redis fork), both BSD-licensed.

I wish RethinkDB was more alive :-\

No one is saying what they did was illegal, but you'd have to do a lot of mental gymnastics to make a case for it being ethical and in the spirit of open source.