I've mainly seen this done when we're deplaning through a single door that is located behind F/C and in front of Y. Didn't bother me, even when I was in Y. They paid more for their seats and it seems reasonable that one of the perks should be first off. On other flights where the exit was at the very front I haven't seen any extraordinary effort to keep the Y pax at bay, but naturally the F/C folk who care get to be first off just be virtue of being closer to the door.

I don't see an issue here.