I'm wearing the male version of those pants right now. They're called The Climbers - and they're the only pair of pants I own. You know those blogging technomads who have only one pair of jeans and a MacBook Air? Well I'm not a nomad but these pants dry fast, are tough, can be worn in semi-formal situations, and have crazy stretch. Jeans don't have any of those features, except maybe some toughness.
Who doesn't want to wear something that looks like pants, feels like sweatpants, and dry after a few hours after being laundered? I launder these about once a month. These are well worth the price.