Why is Pro Stock Dodge down on horsepower ?

Remember the Billy Glidden nitrous story? He hid a nitrous system in his Pro Stock car, passed tech, qualified for a race, then went back to the tech guys, showed them how he did it and basically told the NHRA that other guys are doing it too and they (NHRA) can't even police their own rules. Then told them he's outta there, and went to the NMCA, IHRA or something. Cool.