I ran into this as well and can confirm BMW's corporate policy is to require owners to drive the car for a while before they will disable ASS.
My dealer, fortunately, was very helpful in disabling it on delivery - although the notes in the service report acknowledge the BMW policy and indicate they made an exception for me. I'll try to dig them up and post the exact notes in case it helps someone else argue for the reprogramming to be done.
The BMW response on this, combined with my subpar European Delivery where I also had a negative experience when asking to disable ASS, has not exactly endeared the brand to me.
I get the distinct feeling that BMW feels like my car is theirs, not mine, and that I should feel privileged to be allowed to drive it. It's a completely different vibe from the aggressive personalization that I felt was a core Mini philosophy, and I'm starting to feel like I may have made a mistake in choosing the X1.
It's like there's an angry engineer watching my every move, yelling "KEIN SPASS FÜR SIE!" any time I try to enjoy the car...