I've known some flight attendants over the years, they have total dominion over the cabin and don't fuck around.
My favorite story was about how some TWA attendants would choose regular or decaf coffee for passengers depending on their mood and their assessment of the passengers' personalities, rather than what the passengers actually asked for. Some days everyone on the plane got decaf no mater what, because the guy I learned about it from was tired or in a bad mood and wanted them to stay quiet.
They can and will kick you off for pretty much anything.
That said, this woman was being mildly shitty and entitled, there was really nothing that unusual about it and the whole public shaming on the Internet thing is gross. I avoid using the term "Orwellian" whenever possible because it's used too often and too incorrectly, but it really applies to this stuff.