That's because the rest of the world associates a manual box with an econobox, while the American market demands it for high end sports models.
Ironically, there are more manual models available here than in many other countries despite the US being the country of automatics. For example the South African lineup historically did not offer a manual in 5 or 6 series. Mercedes - no manuals in 6 cylinders, incl c-class, though the vast majority of sales in SA are manual cars.
2011 E90 335i M-Sport 6MT Alpine white - saddle brown
2005 Toyota 4Runner 4WD Sport Edition Silver