I also have similar perspective, we have different levels and jobs in an organisation/company. The type job description determines the pay.
In the aspect of comparing different professions, e.g teachers and doctors. It is well known that teachers are underpaid but comparing them to doctors is a different thing. There are levels to teaching jobs, we also have lecturers, we have some lecturers that collect more salary than some doctors.
Most teaching job salaries are determined by the level you are, moreover the technicality of both profession differs.
RE: Disparity in job remunerations; My take.