To put Mark's point another way, bad is in the eye of the beholder. I don't particularly care for penal desert courses, or courses with tons of water, but many people, even many traditionalists on here, do like these courses.
The closest thing I've seen to truly "bad" courses are the many courses that are being shoehorned into nontraditional areas. I don't know if it's because someone wants to show he can do it, or because these areas are less of a battle regulation wise, or whatever. For example, there seems to be a mini trend to show someone can build a course on the side of a mountain, or a canyon, that isn't really suited for golf, at least in my humble opinion.
Some might argue that the mega dollar monoliths are bad as well, but as long as Tom, Kelly, Gil, paul, Jeff, Forest, Mark, Ian, Mike, Brian, etc., keep building reasonable courses, I'm content to not bash the monuments to ego.