You're going to have a hard time hiding the entire SUV and Light Duty truck market behind an airstream, especially considering neither have transmissions capable of hauling one. Statistically almost nobody tows anything. Of those that do the vast majority tow stuff that comfortably falls within the pulling capacity of a Subaru Outback (or a VW Golf hatchback if you're really feeling rude). Nobody's trying to take anyone's dually away, just reign in the excesses of the auto industry that were mainstreamed by a combination of emissions laws carveouts and aggressive marketing. Hell if this went through we all might start seeing approximately affordable vehicles on the market again and I feel like that would be a welcome change.