Really, just forget about moral aspects. It's business. As long as it's legal, people will do it and not think twice about it.
hyperkik, regarding Fair Use, I would love to argue with you how what search engines do does NOT fall under fair use and I'd love to demonstrate to you how search engines that use snippets DO do harm to webmasters, but, I've said it all before and no one listens because they've all already made-up their minds.
You think scrapers are bad. What are you going to do about it?