I think you're missing the point. No one is saying that developers should be ok with getting less money when they can get more. The point is that as an employee

I think you're missing the point. No one is saying that developers should be ok with getting less money when they can get more. The point is that as an employee, you bring certain value to the company. And that value is often capped not by your skills and productivity but by the type of company you work for. And there are less companies in Europe of the type that can afford to pay very well.