How do some writers get so arrogant?

I stumbled across this link on a message board http://booksandpals.blogspot.com/2011/03/greek-seaman-jacqueline-howett.html?commentPage=1 to a blog that posted a two star review of a self published book released through Kindle. The reviewer said that the book was mostly okay, but had some serious grammer and sentence structure issues. The author went nuts!! Her responses were insanely arrogant. She claimed that her writing was fine, that the reviewer read the wrong version of her manuscript, she posted examples of five star reviews she had gotten on Amazon, demanded that the review be taken down, called the reviewer and his followers names and even dropped the f-bomb not once, but twice!! I was in disbelief as I read the comments. I know harsh reviews and critques can hurt. I've gotten more then my fair share. I've even sunk in to temptation and responded to a few and defended my work. It's a mistake, don't do it. It's unprofessional and ungrateful. When people take the time to read your work you need to thank them even if you privately thought their opinions were rubbish. Writers NEED to develop a thick skin. Writers NEED to be able to take the good comments with the bad. It can be hard but sometimes you need to hear that your plot sucks, your main character comes across as a bimbo, or that your grammer is terrible. It is that sort of brutal honesty that is needed to make writers take a step back and look at their work without rose-tinted glasses. Bad reviews are apart of a writer's life. We need them to be able to see what we did wrong in this story and how we can improve our next one. I had someone call my main character 'Too stupid to live' in a recent critique. It hurt my feelings, but I thanked them for their comment, and said that I would make changes to the story to make sure that she comes across with a little more brains in her head. It is important to always be professional on the internet. Once you write something on the net it is out there forever. This poor woman might have ruined her career. Her comments have gone viral and are all over facebook, twitter, and various message boards. God only knows how many New York agents, editors and publishing houses read her immature responses to all of those people on that board. I mean, seriously, how dumb could you get? Does this woman know the defination of the word professional? You cannot spit in the faces of your readers and the entire publishing world and then still expect to be taken seriously and with respect. The funny thing is it is not just unknown writers suffering from truly epic arrogance. Check out this snarky letter from Anne Rice complaining about bad reviews on Amazon: http://karenknowsbest.com/category/anne-rice/ Wow. I can't believe how rude she was in that. And not just to her readers but to her editors as well! How do some writers get this arrogant? How do they become so obbessed with their own work that they cannot fathom the idea that their writing might not be perfect and that heaven forbid someone might not like it? The problem with some writers is that they treat their books like their babies. They spend months and months working on them and over that time they fall in love with them so deeply they respond like a mother cat if someone dares to critcise them. The claws come out and they hiss and spit. Writers need to learn that their books are NOT their babies and that their writing is not perfect and can always be improved.