It is taboo because things like IQ matter, economically. In the past, height and brawn would be seen as equally significant discriminators, but we have grown ov

It is taboo because things like IQ matter, economically. In the past, height and brawn would be seen as equally significant discriminators, but we have grown over that as cultures. In the future, AIs will make us all equally dumb and intellectually lazy, then we can get over it. Another thing is the sciences which deal with these matters are highly politicized. It's always been hard to establish facts on empirical results alone because they are not purely sciences, they keep a lot of "art" in them.