The Nostr protocol does not discriminate who can have a private key and sign events with them. So anyone is welcome to use the protocol. Communities of people, however, throughout all of history (whether on- or off-line) tend to distinguish between desirable and undesirable behaviors, and people who display desirable behaviors are welcomed into a community, and people who display undesirable behaviors are not welcomed or they are challenged to change. Maybe the expectations are unrealistic or perfectly reasonable, but it’s just how communities of people operate. There is no technical limit to what types of communities can grow on Nostr. But within each community certain behaviors will be accepted and others will not. Multiple communities may share values in common, and others may deviate from each other. There is no singular “Nostr” but rather people who use it, like the internet, like bitcoin. I only need to welcome into my timeline the people and behaviors I find appealing/acceptable. But if I shun other types of behavior and the people who exhibit them, I am not excluding them from Nostr.