I've worked flights from which passengers were removed for horrific body odor. I was involved in an incident in which pugnacious passengers were kicked off after a fistfight. I've seen passengers ousted for being drunk, unruly, high on drugs, low on morality and for wearing "offensive" clothing.
On July 3, a man was removed from a Spirit flight at New York's LaGuardia Airport after taking off his mask and refusing to put it back on. Police were summoned to the gate as the man protested his expulsion.