I think it's much more sentimental than anything else. You don't buy an Italian suit that's designed in Italy and assembled in China or Vietnam, as you wouldn't buy a Swiss watch that's designed in Switzerland and assembled in Japan. I don't care if BMW lifted the Regensberg factory from the Earth, transported an entirely German workforce and had them all get doctorates, I still wouldn't want them assembling my 3 series in Mexico, the US, or anywhere else for that matter.
Yea it's not economical, and it's not rational. But when you get behind the wheel of a BMW and drive it, those things aren't usually what you experience. You experience a feeling, some might even say a sort of cathartic moment. People buy cars because of the way they make them feel. This is true even for the most basic of transportation. If it weren't there wouldn't be more than one color or style of even the most basic economy cars.
Being made in Germany, and for that matter Bavaria, is part of the BMW experience. You may not be able to smell it, see it, hear it, taste it or even touch it; but still you can feel it. The human mind is incredible, and once told the car is no longer built in a specific locale, for me-and I would hazard to guess for many others-that feeling changes. Whether or not that feeling should change is entirely immaterial once the change has occurred because by then the damage is done.
Don't get too bent out of shape-just my opinion.
And for the record, the FWD infuriates me, but I wouldn't consider it anyway.