Lots of it. People beind mad that their Mastodon posts ended up on Bluesky, mostly. There’s a Github thread that includes a recap of most of the drama.

A section of the Fediverse sees the Fediverse as a separate thing from the big companies and other social media and wants to stay isolated rather than federate as widely as possible.

It’s possible to simply not federate outside of a specified whitelist, of course, but that doesn’t seem to be what the people complaining about the bridge want either