If that's how his students dress, then what's the issue?
At least he's not teaching at one of those alternative schools that allow the kids to dress as junior furries and has little cross dressers and fem boys all over the place because "At this school, we believe in a child's right to express themselves how they see fit instead of fitting into oppressive gender-normative roles" or whatever politically correct word salad they use to manipulate people's emotions.
Type of fakkit school the typical Reddit liberal would send their kids too.