He didn't actually get rude until after it was obvious he wasn't getting any help other than the pathetic 10% discount. I probably would have been rude too! I think it's rude to take the amount of money that Parallels did and then not release a patch to at least WORK with Mountain Lion. Nobody ever said they needed to give away new features for free, but WORKING with an updated OS isn't a feature, it's a given. Like so many others Parallels was the ONLY piece of software on my mac that wasn't compatible. That's just plain irresponsible on their part, and shows what a lazy and greedy company they are.
However, like I said in an earlier post I'm really happy with Sun's free Virtualbox. So happy in fact that I've just uninstalled Parallels 6 and deleted my win7 image. I'm to the point now that even if they offered a free patch I'm completely lost as a customer. Way to go Parallels. I didn't even know Virtualbox EXISTED until after I had to come here for support and found there was none.
I'm not disagreeing with respect to Parallels, but there's no need to be rude to them, no matter what. He could have expressed his anger without being rude. To be frank, he comes off like a petulant child. And where did it get him? Put yourself in their shoes, would they rather please a customer who is being calm and logical, or one who is insulting them?
Just tell them you are not happy with their service and will be planning to switch to one of the alternatives; no nastiness necessary.