I don't think you should compare a airline pilot to a GP but rather an airline Captain to a GP.
How long does it take to train a person up to a GP? 7 years maybe??
How long does it take to train a person up to B737 Captain? 7 years..maybe more!!
Both occupations are no more important that the other...if you mess-up people die simple as that. However the financial rewards are a different story.
I am a GP in the UK.
You can train to become an airline pilot in, what, 18 months? At that point you are a first officer and are qualified to fly the aircraft yourself in the event of an emergency. If you then fly, say, 800 hours a year you could reasonably expect to become a captain, with a bit of luck and a following wind, in 4 or 5 years?
To become a GP, you need top grades at school, which you don't for commercial flying, you then go to med school for at least 5 years (many do 6). That gives you limited registration and qualifies you to practice under supervision for two years. If you wish to become a GP you then have to undergo a minimum further three years' training. At that point, an absolute minimum of 10 years after entering med school you are viewed as a very wet behind the ears newly qualified GP with a lot to learn. As an example, in my small rural practice we are very wary of hiring such inexperienced GPs as locums because they have to practice here so much on their own and under such pressure. GPs are not reckoned to be really seasoned until they are at least five years qualified (as GPs), so, say, a minimum of fifteen years after entering med school.
I don't have any position on what airline pilots should earn becasue they carry enormous responsibility and are under enormous pressure, but in educational / qualification terms GP and airline captain are not comparable.