Getting banned feels bad, regardless of any "parasocial" relationship there is. If you're banning someone because they offended you personally, leave it at that. You're just being a dick if you ban them in others too.

Just because it's in their right to ban people willy nilly doesn't suddenly mean people can't critizice their right to be assholes.

And even then using parasocial as an argument as to why people aren't allowed to care that they get affected negatively because of someone else's insecurity is just ridiculous. Like sure if the user is regularly making bad comments, but when it's just a slight offense to a specific person, do they really deserve that?