I really don't see the issue. So more users is bad? I thought our issue is the lack of users currently.
I've seen people complain about ads and data harvesting here. But instances can already do that. Meta joining would change nothing about that. Actually, being a proper legal company, it might be easier to sue them over misusing your data than random instances.
"Embrace. Extend. Extinguish"? Let's stop between the last two steps then, not before the first one.
Kbin would be crippled by the amount of Threads content? I thought federation only happened if one kbin.social user is following a user on Threads? Should be as easily manageable then as Mastodon is currently. Or am I misunderstanding how this works?
To me, big sites federating looks like a clear advantage. I don't really get the big problem.