Stuckgear, in the case of the Underground this is right on the money.
what it seems to be is that the salary is there, because, quite simply the tube is a monopoly, strong union with a weak LU management that does what it must in order not to upset its service levels.
The overground nation network is also essentially a closed shop. To become a train driver you have to be trained by a TOC. No external training agencies. It would be futile to start one up because if a prospective train driver coughs up the equivalent of a full ab-initio to frozen ATPL and cannot find a company willing to take him on he can not even drive trains for fun. (Preserved railways excepted but you will be selling tickets and polishing locos for many years first).
I do not know what the airline industry can do to reverse the current system where we have a great number of aspirants to the RHS and the ability to independently train to fATPL standard. Probably nothing as it is not in their financial interest to do so.
Just a word on the standard of new '5 minute managers' that have been popping up over the last few years in the railway industry. Armed with a third from a former polytechnic they see the railway, LUL and Notwork Rail especially, as the last refuge of the desperate. This is where many disputes have their origins. Urged on by more senior management to implement change for profit (they wisely keep their heads down) they try to implement change without knowledge. When it backfires they are 'let go' and more cannon fodder recruited.
Roll on retirement.