If you're going fast enough then there IS a benefit in less air drag - which is the main reason for their existence.
But maybe there's a handful of riders who prefers them for not ever having to be trued.
And probably a big bunch who simply like the looks.
Like high-profile/deep-section rims, they do increase the influence of side winds. And it's generally considered worse to have the front wheel act as a sail than the rear wheel.
There MIGHT be an aero advantage to running them as fronts, as the front wheel sees mostly undisturbed air compared to the rear. Air that meets the rear wheel has already passed front wheel, fork, down tube, rider's legs and seat tube. It MIGHT be that the airflow across the rear is already so turbulent that there's less to be gained from better aerodynamics at the rear.
Then again, if that was the case, there'd be very little to be gained from disc rears, which are quite common in certain kinds of riding.