I'll give it to you that many of my sites would qualify as "thin". However there were also many removed that call into question the value of a search engine that would remove these. Take for example my neighborhood homeowners association. We have a small website where we post the board minutes, contact information, newsletters, bylaws etc. Bing removed even that. So if there is one HOA that goes by that name and when you search for it you cannot find the official website then what good is a search engine?