What they probably meant by a commuter helmet getting knocked around was that it gets use daily, versus a helmet that just gets used twice a week. You'd be looking at 2.5 times as much use, which means that many more times it gets moved around... just how gentle you are with it, the lbs can't really say.

Mine is OLD, almost 10 years probably. I'll be replacing it mainly cause the fabric covered foam straps are deteriorating. The helmet itself still looks perfect... not a scratch, chip, dent.... I treat it like a fragile commodity.