I just got back from a long sabbatical in Spain and 1 through 3 I'm with you. Why do people just accept flys in their house? Why don't the windows have screens?

I just got back from a long sabbatical in Spain and 1 through 3 I'm with you. Why do people just accept flys in their house? Why don't the windows have screens? I don't think I saw a single screen on a window the whole time. Drove me up a wall. At least AC is decently common in Spain, at least more common than I've seen in most other major European cities.