Also, you can initiate your skid sooner. If you think "I need to skid" right at the moment your right foot is passing 90 degrees on the way down, its too late to skid on that revolution and you've gotta wait until your right foot gets all the way back around. On a typical 700c tire with mid-70s GI, this is about 6 feet later. Can make a big difference.
If you can skid both ways, you'll only have to wait 3 feet.
If you have a brake, you don't have to wait ever, but that's a different discussion.