I'm trying hard to both try to reason out the "why" of SUV's and rationalize how it is that they became so big, so prevalent.
I *hate* it, going into a grocery store parking lot, parking, coming back, and finding I'm surrounded by SUV's that limit my visibility to zero when I'm trying to back out of my parking space. (Introduce some regulation requiring mirrors on SUV's? Har har.)
CAFE is a failure anyway; we use more oil than ever before. Apply some mileage standards to SUV's, and the auto companies would find some way around it anyway. With the exception of pollution control devices like the catalytic converter, we'd be better off (IMO) without CAFE entirely. (And I'm sure you can make arguments that those converters are more expensive in disposal than a non-equipped car.)
The law of Unintended Consequences: Gubmint makes laws, people follow them to the letter. The letter never being what was intended. ("Homeland security department"? Oh god.)