What your forgetting that even if the left shift and the sports option had the same effect (which it doesn't) left shift doesn't change throttle sensitivity / lag , steering weight and if you have adaptive dampers comfort damping..
Same argument. What kind of sport car enthusiast drives a N54 with DCT, pushes the onion button, but settles with an automatic gearbox? It’s poor engineering, and equally bad at understanding the market.
I can appreciate a separate button to fix the gearbox to manual to avoid repeated shifts on certain inclines. But that too can be solved with better engineering.
(I know, in the last 20 years I’ve been very critical of BMW choices.)