You can preach about books all you want, but that's all they are - printed material by one author sealed in time. The fact is it's easier to find more thorough information online. Just because it's in a book doesn't mean it's correct, thorough, or adequate. I have probably 8 books on saltwater aquariums (corals/fish/general) and I probably come here and google 97% of the time.
Your kind of making the point that the information is readily available. If it's important to you to rewrite it then knock yourself out.