I think the author Cory Doctrow (who is actually a published author) laid out his case quite clearly. He doesn't question the intentions or sincerity of the BlueSky team. But from past experience he is not confident that will be enough. We have all been there before. (I am old enough to remember when the likes of Google, Facebook, Twitter, Instagram, etc. held themselves to similarly lofty ideals and standards.) But under pressure whether it is financial pressure or political, regulatory or or from investors, employees, the board, competition, etc. Bluesky may very well choose to renege on those promises to their users- This is enshittification. The only guarantee against this is if Bluesky allows users to seamlessly migrate their account (including posts, followers) to another host without any disruption or degradation of their service.