Hi @Georg I think they're connecting because some (many? all?) of the pubs follow each other so they're connecting to get your latest posts because they see you are friends (mutual follow) with a pub they are friends with. It is nothing to worry about :)
Welcome to Scuttlebutt! It's a little confusing at first but it start to make more sense after a while. If you have any more questions, please ask. It's late here so I may not see any reply you send until tomorrow but hopefully someone else will jump in
If you feel up to it, it might be nice to say a little about yourself here in the #new-people channel so that others who share your interests can see and say hello!
Have fun exploring.