Maybe a bigger niche than they think
I think the folks at BMW have just stereotyped Americans several years back and are clueless about how big the MT/not too big vehicle/good mileage niche may be. The country may be changing too.
I live in Ozark Missouri, and I would jump at an X1 or a wagon if it came in manual transmission (and even better, MT plus diesel). I will absolutely not spend that kind of money on an automatic transmission I won't enjoy driving on the other hand. I know many friends and family who feel the same way and don't have many buying options. It wouldn't take BMW that much to get their MT and diesel European models certified for North America, and if they want, only available for European pick-up or special order.
An example of untapped niches: I got interested in BMW after I tired of the seating position of my cruiser motorcycle. Did some research and came to the conclusion that the BMW motorbikes were the best (enduro line for me). No dealer near me in Missouri, so I bought one far away (F650GS). Now everyone around Ozark and Springfield stops me on the bike and asks where they can get one, swearing they'll drive to Arkansas or St. Louis to buy one if they have to.
Could be the same thing with the X1 in manual/diesel -- plus a modest amount of advertising. Sell the driving experience, while everyone else is just doing AT get from point A to point B.