My understanding is, to reach content found on other kbin instances, it is not necessary to create logins on them and go to them, rather the content on those instances can be "rebroadcast" to the instance you have an account on. You don't go to the content, the content comes to you. Likewise content you generate on your "home" instance can be rebroadcast to other instances.
I realize that's an optimistic assumption, one that I can't prove. By what mechanism the content is rebroadcast, I do not know.