I have to disagree just to keep things interesting...and be honest.

1. Yeah, they're associated with jocks, sexy! ...but so is jock itch and so are athletic cups...Do we drool over those?

2. They manage to show too much and yet too little (as G-strings do).

3. They visually distort the ass, especially if that ass is not 100.00% perfect - 0% fat. The elastic band eats into the bottom of the butt cheeks and makes the ass "overflow".

4. They partition the body in an unnatural way. The "framing" effect mentioned in an earlier post is really more a distraction from the continuity of the body (upper legs to lower butt...lower back to upper butt).