Pure spite. You could try to dress it up in safety or DEI nonsense, but at the end of the day, this is all about right-wingers getting back at the dirty ----- who have been out in the open for too long.
If you were to cook a MAGA down to a sauce reduction, you'd get an oily, putrescent slurry reeking of unwashed feet, rotting ginkgo fruit and intolerance.
They don't actually believe in American principles. They just like flags and men in uniform and explosions. MAGA has enabled them to feel safe espousing their tribal disdain for vast swaths of society and a need for authoritarian control by wealthy white male elites.