It's so important for writers and illustrators to develop a thick hide in this business. If you don't, chances are good that you won't be able to handle the critiques (solicited or not) and bad reviews. Learn how to take negative feedback gracefully.
And never EVER publicly respond to a negative review. This applies to friends of authors as well as authors themselves.
Writers not writing for a living often find enjoyment and small payouts from Web sites seeking material to raise their sites higher in the search engine rankings. Although this is a legitimate practice, the writing being published on the Web can often be less than professional. This lack of professionalism distorts the line between qualified and amateur writers. Writing standards are often not the highest priority as Web sites seek to drive traffic to gain advertising exposure. It seems as if readers are not as concerned about the writing quality, as long as they find a relevant account on a particular topic.