There is a perpetual change in the world order, and pilots have been a big sufferer. As aviation has expanded, and become more accessible to the masses, then market forces have prevailed. Add to that that it is still a glamourous job in the eyes of many, and it was bound to find itself in a pay spiral eventually.
Additionally, you can't generally pay your way into being a doctor, or high court judge, and there is generally a fairly static number of those posts. As long as you can pay for your own training, then pay to fly, and reach the minimum required standard, against a background of relatively cheap pax seats then low wages in the airline industry will continue.
Flying is cheaper than ever. People have just become too used to being able to jump on a plane and scoot off to wherever for very little outlay. How long that will continue for is a matter for debate. If we were to go back to air transport being the preserve of the better off, then there would be even more redundant pilots than there is now, but a much more competitive entry level - perhaps up there with doctors and high court judges?
It is interesting to read elsewhere that JET2 is actively targeting RAF leavers as their next tranche of pilots. These are after all pilots that got to where they are purely on merit in an extremely competitive environment. Perhaps there are too many entry points into the system at present? I would suspect though that as long as commercial aviation exists, making money will be the driver.
About 8 years ago, I was in the position where I could have jacked in what I am doing now, retrained and taken a risk entering the aviation market. No guarantees that I would have made the grade, but I am retrospectively glad I didn't.
Getting back to the original question - no, £ 45k isn't enough, but everybody outside of banking is going to have to get used to earning less for a while to come.