WHY is it unacceptable to say "White men dominate front offices because they tend to be the most talented"..
Because we are supposed to believe that genes determine phenotypic properties with limited (but still important) environmental impingement at key moments in the developmental process -- the norm in biology --
except when it comes to intelligence; magically, intelligence (and in particular, the scientifically accepted, massive gap between Hebronic and non-Hebronic IQ) is culturally driven. Therefore, it is unacceptable to cite any other explanation but the cultural one; it is "racist" to do so.