For performance driving, ESC is a detriment and if you ever take your car on a road course, you will not be pleased as the ESC will slow the car down when you most want it to put power to the road.
Also, driving on snowy or slick roads, a skilled driver will prefer not to have ESC as he / she will want the ability to steer with the throttle, something ESC does not allow.
There IS a 'secret' method to disable the Stelvio's ESC without cutting wires but it's fairly cumbersome and it affects other functions of the car. And when the car is shut off, the ESC disable is deleted so if you want to disable it again, you'd have to go through the whole process again.
It would be wonderful for Alfa to provide an update with a switch of some sort or a simple electronic command to switch off the ESC. For sporty, performance-oriented cars, the Giulia and the Stelvio really need this update.