Every time I hear about salaries in London it makes me mad. Why is the pay so bad? How is it possible that the value isn't recognized? Are you able to demonstrate the value that you bring, or is it so much an old boys club that dev's are thought of as factory workers?
On a related note - why aren't there more senior software dev's building their own businesses? It seems like you have so little to lose.
Yes, the old class system. Engineers, no matter how qualified, better even than managers, are "blue collar" workers still. Better to have the right tie, played the right sports, and your father to use his network to give you a leg up. Even if you only have a a Third from Loughborough or Aberyswyth or Durham or some other joke university.
Only the City pays fair market wages to technical people, because contrary to popular belief, the old boys were ruthlessly driven out in the 80s.
On a related note - why aren't there more senior software dev's building their own businesses? It seems like you have so little to lose.