Most of the hate was directed at the developer who created the bridge and appeared as replies to his post announcing the bridge. Unless you were following him, or visited his channel on his website, you probably would have missed it anyway. The developer seemed to take it well and listened to people's feedback, but some people were inexcusably mean and hateful. Lots of F bombs directed at the developer. And there was a lot of ignorance about how the fediverse actually works (i.e. most didn't know that their posts are already federated beyond Mastodon).
When AT Protocol officially federates, Friendica admins will have the option of turn on AT protocol support natively, which means that Friendica would become a server on the AT protocol network, just like Bluesky. It will probably be one of the first implementations of AT protocol outside of Bluesky itself. Friendica also supports ActivityPub natively as well, so if an admin has both turned on, they are operating on both networks simultaneously. That's why they are listed on both sides.
Scuttlebutt is an interesting protocol. It is designed for social interactions using devices that are not always connected to the internet or not connected to the internet at all. Devices basically pass on messages to one another without the use of the internet. (At least that is my limited understanding of it.)
The nice thing about platforms like Friendica, Hubzilla, and Streams is that they are big on user choice and control. So even if your administrator activated it, you still have some control as a user as to whether you see posts from Bluesky.