I don't see whats BS about it. Its the typical handling of emissions programs across the nation. Older cars get exempted since there aren't as many on the road, new ones get stricter regs, now including the diesels.
Whats BS is the fact that the EPA has always been stupid about the emissions regs on diesles, causing us to not get the diesel powered versions of dozens of cars. THis means we've burned far more gasoline than need be, and not had the savings that could have been seen with diesle powered cars.