My apologies to truckflyer for doubting his point about doctor admission I was clearly wrong about that and I will edit my original post.
The point that I was making about oversupply and what causes it still stands though.
Another thing at the route of oversupply and poor T&Cs is that fundamentally aviation is one of the "dream" jobs insofar as the majority of people do it because it is what they have always wanted to do and will accept low pay as the price of that dream. Despite mass air travel, the locos and general loss of glamour in the industry it still carries an X factor about it that very few other industries do. This is why, more than anything, it does not follow the laws of supply and demand.