I'd turn that around. Airlines are very corporate, risk averse and liability aware. I would guess airline pilots are trained and reminded to declare emergencie

I'd turn that around. Airlines are very corporate, risk averse and liability aware. I would guess airline pilots are trained and reminded to declare emergencies in general and specific circumstances, or lose their job if not their aircraft. A GA pilot may not want to embarrass themselves in some circumstances. Is my guess. EDIT: I would further guess that there is some statistical regularity for airliner maydays, and pan pans.