Why? Is that an "element of surprise"?
BMW realised that not all of their automobile owners care enough to do a spare tire change by themselves (either call a garage, a tow truck, get Arnold lookalike to help on a roadside replacement, etc.) so in the end: they too, did away (weight and space savings) with spare repair kit instead of a doughnut or a full spare.
Glad that in my case: wifey's 04 camry still has a full-size spare in the trunk. Guess whose doing the spare tire change?!
(*grin*)
Q.