their central argument:
[…] but the gist was that Instagram had reached out to one of the larger Fediverse servers and asked the person who runs to have a meeting 'off the record'. That person turned them down and told other members of the Fediverse what happened. The general consensus is that this was going to be a monetary offer to allow Instagram to further colonize the Fediverse by purchasing one of the larger servers.
And therein lies the problem: if the majority of users gravitate to a few large servers, then that leaves those larger servers vulnerable to exploitation.