The reasons you listed are exactly why I can't stand him. I don't buy the crap he sells out of principle.
What I don't understand is when you see the stuff in the drugstore, the packages have a big picture of him captioned, "AS SEEN ON TV WITH BILLY MAYS," like it's a celebrity endorsement or something. How, exactly, does an endorsement by a guy who sells detergent on late-night TV sell anything??