sweatpants, appeal of?

Since I came to work at my current place of employment -- (a PAC-10 major research university) I have noticed one peculiar form of dress for the men. Can anyone say sweatpants? For several days I've been trying to decide what the appeal is. There are definitely two factions: the jock, and the geeky guy who would've worn sweatpants even if they weren't en vogue. I've come up with two scenarios:

1) Practicality/comfort - Sweatpants are easy to put on, they have an elastic waist, they don't really get "wrinkled" so don't require ironing or a "refresher" in the dryer. Typically they're made from cotton so clean easily too. While these are fairly convincing reasons, please read on.

2) Appeal (could it be?) - Initially this didn't even come to mind. Sweatpants always seem like they're bulky and shapeless and really just .. well, unattractive. But then, I started to pay attention to detail. These things can reveal more than the tightest jeans in your dresser. I didn't think I'd ever see such well-defined packages anywhere other than underwear models in catalogs. I'm wrong! You also get some pretty amazing definition of the rear-end too. The different types of sweatpants come into play here, the lightweight and somewhat "clingy" fabric, all the way to the thick and bulky fabric.

It's definitely not just athletes that are wearing them, all types of guys are wearing them...some with more success than others. An interesting phenomena, I wonder how much longer it will last before this crop of men try to assimilate into the girl jean fad.