This stuff happens by default on GitHub (and similar places) because GitHub (and similar places) gives everybody the illusion that every user is equally legitimate once they've passed the initial phone KYC sign up process.
In Nostr there is no entity to say who is a valid user and who isn't, so in the long run everybody is forced to use some kind of filter, otherwise they will drown in spam.
I believe the best simple method for such filtering, when browsing an unknown place like a thread on someone else's profile (or git repository), is to only fetch stuff (replies, reactions, proposed patches etc) from the relays announced by the profile/repository you're browsing.
Assuming software is made to use that filtering method the default, then it becomes trivial for the repository owners to control whose comments get to show up to an unwary passerby.
In Nostr there is no entity to say who is a valid user and who isn't, so in the long run everybody is forced to use some kind of filter, otherwise they will drown in spam.
I believe the best simple method for such filtering, when browsing an unknown place like a thread on someone else's profile (or git repository), is to only fetch stuff (replies, reactions, proposed patches etc) from the relays announced by the profile/repository you're browsing.
Assuming software is made to use that filtering method the default, then it becomes trivial for the repository owners to control whose comments get to show up to an unwary passerby.