The work permit regulations are quite complicated, you can get a work permit if you have a profession that is a skill that is required!
However with the high number of unemployed pilots in the EU, it is not a skill that is required, therefore they will never give you a work permit for this.
The same applies for USA and Australia! This is one of the reasons change of Visa regulations for the USA recently, which has made it much more difficult to work as an instructor in the USA if you come from abroad.
Another thing, why would the airlines bother to spend time and money and making work permits in the EU, when there are loads of pilots that have the right to live and work in EU, which does not require such administration or extra costs!
Not sure about pilots going to Turkey, but I would guess it would be very experienced pilots, that they might need there, that is not sufficient from own country, that would at least be the EU requirement!
However in the EU there is no lack of this at the moment, contrary there are thousands working outside EU, waiting for the chance to get back home again!
It is not impossible to work in the EU, but than you will have to choose a different career!
If you visit UK home office page/consulate, regarding how to get work permit, you will see how complicated it is to get a work permit! Also UK are not member of Schengen, so even if you managed to get permit for UK, that would not give you the right to work in any EU countries!
UK have millions unemployed, there is no good reason for opening for free market from Turkey, as there would only be a flow of work force, that would undercut todays already very strained job market!
This is not about prejudice, it is about preserving the economy, at a standard that gives people of the nation a chance to survive.