I'm putting my head very cautiously over the parapet here. I'm know a lot of pilots and people who have worked very hard (and spent a lot of money) to become professional airline pilots. (I'm a PPL.) I understand it's a responsible job where you cannot make a mistake.
It is obvious that terms and conditions for airline pilots have become worse over recent years.
It's partly related to the fact that there are more flights. Passengers do not consider flying to have the same high status as they did, and so are not prepared to pay (in relative terms) as much. Low cost airlines work on the same economics as cheap Saturday day returns on the trains. (I am NOT comparing pilots to train drivers here.)
It is partly due to over supply. There are more airline pilots available than jobs. Airlines don't have to pay to attract applicants. I don't think this affects the 'senior end' as much, but it must have a knock on effect.
I think it is also a reflection of what is happening in society as a whole. Teachers work longer hours and are continually checked; nurses can earn more money, but only if they take on much more responsibility; new council workers work a longer week; many people now only get the minimum of 20 days holiday a year, including Bank Holidays; many people only get pay rises if they take on more work; some workers are made redundant and the remaining workers have to do their jobs as well.
Statistically, in the 1950's and 1960's wages, for all sectors of society, rose on average in relation to qualifications/experience. Now wages only rise gradually until you reach the top 10% in any job/profession/industry, when wages rise dramatically.