It's less hilarious when whole country policies are made on those assumptions thus ruining it economically (notably), and voicing any concerns is threatened with legal force.

In France the official dogma of the educated is that every difference is cultural, and races don't exist. My father for example strongly held and defend those beliefs. Somehow he gets very angry when I ask why there is wide academic achievement difference between his children despite growing in the same environment, or how Japanese people could instantly guess I'm a foreigner while not uttering a single words. I think that deep down all those people know the truth but they don't want to admit it, nor admit it to other for fear of the social consequences.