You know, it actually could be that the 10K interval is the result of bean counters for the reasons stated above, especially given the annual oil change policy as well. I got an oil change when I hit the 1-year mark even though I was only 2000 miles shy of the mileage mark, and apparently BMW's policy for time-based oil changes is that they do NOT reset the service indicator, so 2000 miles later I got yet another free oil change due to mileage.
As for the free oil between changes, in the 20K miles I've driven my car, I've gotten 5 free liters of TWS 10W-60 outside of the regular oil changes, 4 from my SA and 1 from another dealer when I ran out on the way to a track day. I didn't end up having to use all of that in my car though; some spilled while in a Ziploc in my track bag (I hate that the caps don't reseal tightly). I don't know if that's BMW policy or simply a dealer courtesy, but that's been my experience -- though I imagine it would be considered Ultimate Service since the car is saying it needs oil, and oil is covered by Ultimate Service. Although just in case it was a dealer courtesy, I did buy my SA a bottle of JW Black Label for Christmas last year.