Traditional social media also has downvotes, that's what demonetizing, censoring, strikes, etc are. It's just that on those platforms the "downvotes" are carried out by the site moderators and not the users directly.
I think that the bottom line is that she was upset for losing rewards. I don't see her abandoning youtube or twitter over negative interactions with other users. That should give us a hint of the real motivation to ditch Hive and the rest is just a rationalization on her part.