@Anonymous
I'm with you on this one.
It's difficult to say without knowing what the issue was and the tone of voice can easily be misinterpreted with texts as apposed to verbal conversations. @Loretta126 felt like she was being yelled at, but perhaps it was not the guest's intention to come across that way. Who knows?
However, if the guest was actually rude, I see no excuse for it and would not let it slide.
Early on in my hosting experience, I had a guest really bark at me and threaten me (not physically but with the implication he would leave a bad review) because I wouldn't turn the heating on in the middle of summer. Apart from anything else, other guests had their windows on and would not have been happy about the heating being on. It was summer! Still, I managed to appease the guest by giving him an electric heater for his room. It always irked me though that I let this man speak to me that way.
More recently, I had a guest really harass me about something mentioned in the listing. Whenever this happened, I would try to offer a solution but he would just stomp out of the room. He was sat down and told in no uncertain terms that it was not okay for him to speak to me that way in my own home and that, while I of course wanted him to be comfortable and enjoy his stay, I would not be putting up with rudeness. I got an apology. The guest didn't stop complaining but he stopped with the rudeness. I know we are in the hospitality business, and some might say that the customer is always right, but I don't think that means they can treat us like dirt.