I heard it originated in prison, but differently. Wardens would give out ill-fitting clothes to humiliate the inmates. So people on the outside made saggy clothes "cool", that way the badly-dressed people on the inside would feel normal. It was just solidarity with ill-treated prisoners.
When I was a kid bullies pulled your pants down to your knees to embarass you, I guess now they pull them up :-)
But more seriously kids get to an age where they want to declare they are not their parents, the go to method of choice has been clothes since well since forever. The cycle is that the kids wear it, its shocking, then as they get older they are wearing it as "adults" which then makes it establishment, so the kids behind them make up some other fad. Rinse and repeat. I think making dress code laws is both absurd and hopeless.
A corollary: everyone detests looking like his father, nobody minds looking like his grandfather. My brother and I would not under any coercion worn shorts with dark socks and dress shoes, as our father routinely did in warm weather. Some kids don't mind that now. Think also of the "Teddy Boys" of the 1950s, wearing the clothing of the Edwardian period ca. 1910.
Yes I suppose it is. I guess I should say it the other way. I'm impressed with the long-botheredness of people in power regardless of the intent of the people wearing the fashion. Most of the time parents, clergy, etc give up after a decade or two and accept something as normal.
Do you really think wearing your pants down over your ass is going to reclaim your dignity? If so I got news for you - it's going to do the opposite. If that's a surprise to you then I'm surprised myself. If you object to it then yell at the sky, because it's just as likely to change things. Welcome to the real world, where these things matter.
