> so they “punch up” at the only sort of foreigner that is likely to make a positive contribution to their country
Honestly I doubt they are punching up in many cases. Sure, the Americans who holiday in Sicily are probably pretty well off, because that's expensive. But a lot of the tourists who visit the large Spanish cities or coastal towns are working class people from northern Europe for whom it may actually be cheaper to get a Ryanair flight and an Airbnb for a couple of days than to take a trip within their own country. I don't know anything about the kind of person who sprawls this graffiti around Barcelona but I suspect there's a good chance they (or their families at least) are wealthier than the tourists they are raging against.
Honestly I doubt they are punching up in many cases. Sure, the Americans who holiday in Sicily are probably pretty well off, because that's expensive. But a lot of the tourists who visit the large Spanish cities or coastal towns are working class people from northern Europe for whom it may actually be cheaper to get a Ryanair flight and an Airbnb for a couple of days than to take a trip within their own country. I don't know anything about the kind of person who sprawls this graffiti around Barcelona but I suspect there's a good chance they (or their families at least) are wealthier than the tourists they are raging against.