Be thankful for it - its another way of ruling out people that are a waste of time to talk to. Its an awful look, uncomfortable, and limits mobility.
Its an extension of the thug look and the counter balance to woman's extreme low cut pants with high thong - it does force men to walk with their legs very parted and forces a swaggered walk - which in and of itself is masculine - I suppose that the guys who go for this look aren't comfortable enough in their own skin(or better fitted clothing) to be "manly"
I used to sag my pants. I don't so much anymore. I did it for comfort. And I never really did it much either. I just hated wearing tighter jeans and such. Then doing somthing active and sweat. Baggy made more airflow. And such. Lol.
I'll stop there for you though. Probably don't want to hear anymore. But
I'd say comfort. For me. But mine never went below the waistband of my boxers. They were just. Big. Lol.
Sagging started in the time when gangster rap was big and because a lot of gangster prowess came from inmates rapping naturally it picked up inmates would get raped and because there bums hurt they would sag it became a style because people wanted to become gangster
I don't think it's come back.. actually I think most guys got the hint that it looked extremely gay and stopped doing it. I don't even want to associate with those kinda guys that sag to the extreme because it's just NOT a good look! I understand the waistband of your boxers showing or whatever, but that's not exposing your whole butt for the world to see... there was this kid in my history class today, and he got up and I swear you could see his entire ass because his pants were sagged so low!!
I know this isn't really an "answer" but where I live- there was NEVER a break in the pants sagging. It really bothers me! But with sweats, if I'm just throwing them on to drive somewhere or whatever, having them a little low feels good. Sexy maybe. It's the exposed hipbone thing.
Guess guys don't like tight pants the way we do. I've seen this a lot at my school, and I think they could acheive the 'gangster' look by saggin their pants. But mostly though, all the guys would wear pants normally but it would be baggy, not saggy.