In terms of driveability, the BMW engines are fantastic. Flat torque curves, lots of HP per pound....
I also believe that for maintenance, the BMW engine is laid out in a much more logical pattern.
Christ, the OIL FILTER is on TOP of the engine. I don't have to spill a 1/2 a quart of oil to change the filter....
The hose clamps are lightyears above anything Detroit has to offer.. Quick disconnects that work....
Also factor in the demographic of the BMW owner to the Honda owner. In general, the BMW owner has more money and can/will trade in his card every couple of years or so... The average Honda/Toyota owner keeps their car a lot longer. More miles...
And think about this, since there are six to 10 time the number of Japanese engines on the road, and for a much longer time, the manufactures have a cubic butt ton of longevity and real world data at their disposal....
Remember the Japanese motto, small increments... and that is just what Ford has done over the last several years. That's why their quality is so much better than the other big three....