If you're building a home theater, sometimes its extremely hard to dial in a 5 or 7 channel system. As inconsistent as the results may be, they are more efficient than the human ear with a tape measure. I rely on my ear and tape, but I swear it took me three weeks to get my system to where I'm satisfied. For most people, they don't have the time or patience to dial in a surround system. Hey, it's less expensive than hiring an audio engineer to come to your home and dial it in, right?
One thing these auto setup systems can't do is place your speakers. You need to get that right on your own. That means center channel height, tower canter, surround height and placement, and rear surround placement and height. Those, IMHO, are as-if not more important than auto setup. If you can get the placement right the first time, then auto calibration should be a snap.