I'm not particularly fond of the hip hugger style of today - it's the rare body that can pull off the look. More often than not, it's just plain unsightly. The late 1970's had its share of ugly denim fashion - the uber tight "spray on" jeans and slacks for men were borderline pornographic. I think even women will agree that, generally, a man doesn't look good in a pair of slacks so tight you can tell what religion he is (to quote Robin Williams). In 1978, there was a very fine line between a pair of jeans and a bodystocking. This is not a good look for most men.
Back the 1970s, girls would soak their jeans in a bath tub and then put them on wet so that they would dry up to look and feel like a second skin. Somehow, this was an attractive look for women IMHO. However, the sight of a gaberdine wedgie on a man is just horribly, horribly wrong.
I'm sure Robert Plant looked just great in his painted-on jeans, but he's a rock star and the rules don't apply like they do for everyday schmoes. I mean, spandex pants were the rage for hairbands in the 80's, but that didn't mean guys had a license to walk around in spandex (thank God). The rule of thumb in the late 70's was the tighter the better. Read the ad above: "... The fit is so snug and provocative, you'll even feel sexy wearing them." Evidently, the girls were diggin' it then.
C'mon, ladies. Was the sight of a male camel-toe (i.e. the ca-male toe) attractive? The outline of the male genitalia in his skin tight disco pants was pretty bad, and I think it goes without saying these guys were going commando. But you've also have to give a little respect to those guys back then - they were putting it out there and they didn't give a damn. The chicks were liking it, and that's what mattered. It was macho and perfectly reflected the sexual revolution. Truth be told, I'd rather see a comeback of the tight pants for men than the ultra baggy look that was real popular not too long ago.