narf
Sgt. Maj. Buzzkill
My thought is that the first generation DSG was being developed around the same time as the B6, so it wasn't included until later. They have been offering DSG on various models since 2006, slowing adding models along the way. You can now get DSG as an option on most VW models here.
Every VR6 B6 came with a DSG over here, since the B6 was introduced in 2005. There are 350 Passats between 2005 and 2010 with 250-300hp for sale around here, not a single manual amongst them.