It's a gross overestimation, and misrepresentation, of the reason your average consumer buys a TDI Passat. It's all about the 42 MPG, and very little about the invisible smoke plumes in the rear view. Unless you're a left wing, environmental extremist. They won't be clamoring to get them "fixed".
You are misiing the point... these non compliant autos can be removed from the road in county & states where they are non compliant to emisson testing unless recalled & fixed. Owners as of today have no idea of what will be their emission solution and did not buy units expecting this problem. What owners do after the recall to modify is up to them nothing to do with VW meeting EPA testing standards.