If their audience will follow them anywhere, then why put in the effort to create a new platform when one already exists that can be iterated on if it doesn't fit their exact needs?
Discussion
because walled gardens.
and even though we like to pretend that the content on the platform does not matter, it does push people away when it is a bitcoin circlejerk
people won’t do stuff free for you, we have to fix the problem
But why does it matter who is already here? If the point is to leave a legacy platform to cut out the middle man, then why create a new platform except for control? Creators can achieve almost any level of control they'd like on nostr.