"The people that go towards things with Alex Ross covers generally don't want to read older comics - they want to feel like they're getting in touch with some sort of pseudo-art that's ponderous and important. Superhero comics, while culturally significant as a genre and a great deal of fun when done properly are not, in fact, important a good 99.95% of the time. It's not enough to tell your audience that something is important because it's drawn in a dark, brooding style and some rape happens within; you have to give them more.
So, it's not enough that heroes wives have to go and get the Law And Order: SVU treatment. Now we have to make sure that people go "Oh my god, this comic is important because that Alex Ross painted that cover and he's a real ****ing artist" in order to get more sales on a title that is going to do gangbusters anyway because it's Geoff Johns doing Hal Jordan?"