Lumping "Europe" together is like lumping Maine in with Texas. There are cultural reasons, historic/housing stock/technology reasons, and, of course, MANY PLACES YOU ONLY NEED IT TWO WEEKS A YEAR, MAX.
Spain and Italy are also big countries that have widely varying climates, and even in the hotter areas the buildings were constructed in ways which keep them surprisingly cool during hot days (and in the hotter areas there is quite a bit of A/C, if not quite Dallas levels). Not every building of course - generally older ones are better for this - but I've stayed in places that mostly handled 90 degree days fine (especially true in hot places that still have reasonable overnight temperatures).
It would be absurd for a couple of days of ridiculous temperatures in Britain (for example) to motivate large numbers of people to install them. Even in balmy southern England, 75 is a scorcher of a day!
Of course exciting trends in climate change could change that, but one heat wave, or even one annual heat wave, should not cause an A/C retrofit in Manchester. Or even Torino.
