terry writes:

Saw a similar comment from a heavy captain on aus.aviation. So why
would they even bother to ask if there was a pilot on board and scare
the **** out of the pax for no reason.

The pilot may have felt that someone else with piloting experience would be
better at providing assistance than someone with none. However, in this type
of situation, that isn't necessarily so. While a trained pilot would almost
certainly not be worse, he might not be better, either. You need someone who
can follow instructions, not necessarily someone who knows how to fly. A
pilot might understand the instructions more easily at first, but he might
also be less inclined to do exactly as he is told, which could present a
hazard that outweighs the utility of his piloting experience.