I don't know if the Steelers stole it as much as the NFL made sure they cashed in on a much more lucrative money-making opportunity. They just couldn't have pimped the "Bus" story, the "Ben" story, and encouraged the Steeler faithful, of which there are hundreds of thousands more than for Seattle, to buy overpriced "memorabilia" and commemorative merchandise.
Let's just hope it doesn't happen again. If the NFL is going to rig the playoffs, there isn't going to be much point in watching it anymore, especially if you root for one of the smaller market teams like Seattle, Cincinnati, Buffalo, etc.