That being said, he sure is full of himself about how important his lectures are.
Well... I could understand (though I’d think it a bit over the top to word it like he does) if he simply said “no talking during my class!” But why specifically would he go out of his way to single out “bless you”, and “flag” it as being “especially rude”, to the neglect of lots of other sayings which I’ll not mention? That smacks of an agenda which is specifically targeting religious speech; it makes no sense, otherwise (e.g. why is wishing someone a blessing “especially rude”?)
I’ve been teaching for 20 years, and having someone say “bless you” never offended me in the slightest (why would it?); even in the few cases where a student was obviously “playing it up” (for laughs, for distraction value, etc.), I could usually end the issue with a quiet raised eyebrow, shaking my head “no” slightly, and giving a subtle “keep it down” hand gesture.
I’m starting to think that this guy is a bit insecure in his classroom...