the room with people in red shirts has suddenly decided to connect with the rooms with the less numerous blue and green shirts
think the red ones should simply return to their own room that they were perfectly happy with until now

go back to reddit. this is the fediverse, the entire point is that these are not, in fact, "separate" rooms. being connected is the default. that's why it requires a giant discussion to kick anyone out.

Where exactly do you see the invitation?

It was posted publicly to all federated communities and absolutely no indication was made that the majority of people to whom the post was sent were unwelcome to participate.

On Hexbear, we have a rule that we have to leave meta discussions of other instances alone if they want us to. All the admin had to say was, "lem.ee users only" and we would've stayed out. If you refuse to take such a simple measure to restrict discussion to your own community, you do not actually want to restrict discussion to your own community.

And the admin didn't. You can go ask him. He was not trying to keep hexbear users out or in any way offended by the fact that we participated in the discussion. Why are you (a member of neither instance) offended on his behalf?