Roger Scruton is romanticizing. He therefore completely misunderstands the expressive functional reality of ordinary homes and security by focusing on public architecture, which everywhere expresses elite ideals instead of common ones.
Take Florence and the Italian Republics. Frequent wars and not infrequently with Muslim empires meant homes had to be defensible and closed off from streets. Only later, briefly, and elsewhere later like in Britain and the US were isolated farm villages open to welcome trade, or US farm homes isolated away from the necessity of group protections because genuine threats had become to rare to proactively defend against them.
Similarly, the divide in the Muslim world is between open plans in port cities secured through trade by larger powers that could ensure protection, versus homes way from ports, deliberately closed off against strangers so as to be defensible against frequent invaders. Most of the Islamic world remains like unstable and insecure early Florence. And homes throughout MENA reflect their isolation and insecurity through closed plans, just as much as Spanish ones from Moorish times do, even in the New World.