I rather suspicion for some it may be the fear of what would happen to them if they were caught standing when the loud speakers went off - I further surmise that the 5 times a day of making like a stinkbug is a mind-control trigger -
Ayuh, well I know what happens in one place ... Riyadh ... the Religious Police... liable to give'em a whippin' with bamboo canes and drive'em to the mosque like cattle. Infidels off the streets, shops shuttered. Although lately, they ain't been stoppin' traffic. One interesting 250 mega-dB muezzin call I heard:
"Come to prayer so that Allah the All-Merciful can give you the strength to slaughter the infidels in our midst at the appropriate hour." Wish I were kidding!
Travel is so broadening!