A large part of the skilled vs semi-skilled job argument is to do with how often a pilot has to demonstrate the kind of skill that can bring a fully laden 200 pax jet down safely given a howling crosswind, rain and 45 mins of fuel remaining. Answer of course depends on where you are in the world but for most of us it's not very often.
Arguably, a very typical day in the world of flying a commercial airliner can be completed safely with a very basic but safety concious effort and it often does. We, as pilots are respected for our abilities to get out of the poo when it hits the fan.
Many jobs out there required similar concentration levels but the numbers required to fulfill the role are low. In piloting terms we have huge supply and a not as big demand, so the cheapest bidder wins giving arise to lowly opinions of the job from within.