People who actually own a G, wll agree it's not a gimmick...
Jip agree with this sentiment
Do some proper miles in both modes and you will appreciate what they are for...
Steering is far lighter in N, making it easier for parking, less responsive engine (though the MA obliges in N at higher revs), the breaks are not as sharp in N either. So in stop go traffic this is the better mode to be in.
And if you see a piece of open road or some twisties then D comes in handy, especially since the engine becomes FAR more responsive, the steering heavier and the prefill on the brakes makes them extremely sharp.
For people who dont actually live with the car, I can see why they think its a gimmick, but I am sure most (if not all) new Alfa owners appreciate this system...
Although it would be nice if one can switch of traction control complete though.. Should have that as one of the flip switches next to the start stop swith or the fog lights switches...