As far as I know,
1) Today?s Europe still is the outcome of Ethnic antagonisms. To argue that England should become a (de facto) province of the United Europe because within the union the English would have superior buying power is not (and was not) a winning argument.
2) To argue the young against the old is also a bizarre argument. In a democracy the citizens who can vote are considered to be equal.
3) A look at the rich in the Ottoman Empire would show that the Christians and the Jews were money-wise better off than the Muslims. Certainly, they were better off before Mustapha Kemal pasha sent them to the other side of the Aegean. Why on hell would they act in a way incompatible with their financial interests?
No matter where, a good percentage of the low class citizens has come to the conclusion (correct or not) that the rich and the educated are persons of diluted patriotism who have more in common with their equals across the borders and less with their compatriots. If so, they who cotton to the EU are perceived as foreign to the nation, to its past, to its present, and to its future.
Just look, if you wish, at the Tea party and the Trump voters who at first glance appear to vote against their own interests.