Don’t know what these Spanish simpletons are complaining about.
Spain is part of the European Union. They voluntarily gave up their sovereignty to join the bloc. A German, Frenchman, Dutchman or Dane can travel to Spain freely, as if moving from state to state in the USA.
Spain voted to become part of the EU, and now they can live with the EU trash. /spit
Tourism became a huge deal in Spain long before there was an EU with Schengen, and long before Spain joined the EU. This was a policy of Francisco Franco’s regime dating to the 1950s. And they pursued it relentlessly.
It was the dictatorship that created the airports, roads, hotel networks (some of the jewels of the “parador” system date to that time). It was the dictatorship that made it easy for British people, especially, to buy beachfront property. And so forth.
By the time Spain joined the EU (1986) the whole industry was in place and millions of tourists had been coming to Spain annually for decades.