Good question... near as I can figure, the US importers only want to bring in the models they can sell LOTS of.
Why can't they order in other models they're afraid would collect dust in warehouses - like Yamaha does with the FJR. There are several models I've seen Americans on this and other boards wish they could buy, but can't. The GSX1400, Yamaha MT-01 & TDM, Kawasaki ZRX-S, etc...