For me, it's that, this site can exist even if BlueSky themselves decide to go on a different path or eventually shut down. It still exists in the ATmosphere amongst the many PDSes and AppViews people can deploy and distribute. But first ATProto needs to be given to someone for governance.

I do think its possible even with atp that it can be walled off in a sort of gmail-like scenario. IE similar to how gmail conquered email by providing the service free at a loss, monopolizing it, then walling off anyone who didnt comply to their rules. not doing ads would maybe prevent this tho