Current expats are a massive issue, especially if they aren't, for example, citizens of Spain. Why would Spain take on a load of British Pensioners? I say this as someone who knows a couple, one of whom has never bothered to learn the language, they left England because they were fed up of immigrants who didn't bother to even learn the language.
Expats in Spain are a good source of income for the local economy....clearly they have pension monies to spend. Some will even set up small businesses and take on locals ....unemployment is far higher in Spain than it is here