But the OP didn't actually say that she thought cash bars are rude. She simply said that she doesn't think guests should have to pay for non-alcoholic drinks. I'm reading quite a bit of defensiveness in the Bride's response. Like she knows she was a poor hostess, and is getting narky about being called out on it (or so she perceives).
It has the same effect though.
"I don't think people should do X" when her friend did exactly that.
I agree. I know, based on my friends list, that posting on certain topics will upset certain people. Obviously I don't live my life trying to protect every single person's feelings, but the fact is - if I *know* X person has done Y and I plan on posting that Y is wrong, I should expect X person may be offended by that. It's fairly common sense. I'd be surprised if the OP didn't at least have that wedding a teeny bit in her mind when she posted that, given the other offences of the event and that it is still relatively recent (3 months isn't that long since a wedding).
It doesn't magically make the bride right or her choices right, I still think it's horribly poor hosting and will make her wedding remembered for all the wrong reasons. But nor do I think she's rude for defending herself... most people tend to defend their choices!