Not quite true, Dirty Harry.
One common reason for Brit expats being employed overseas is lower labour costs (no social security/tax liabilities). There is also the additional carrot of less unionisation problems.
As others have said, if all the Brit expats came home, there would be many hundreds more pilots on the dole queue.
I still can't figure out where you get the idea that jobs in the UK/EU belong to Brits...