Because it's stupidly wrong. He misses the possibility for average people to have high IQ children. The sentence parses as : 14% high IQ children are from lower IQ couples, 0% are from average IQ couple, 86% are from high IQ couple...
It also dismisses the existence of mismatched IQ couples, and highly intelligent men with a hot air head isn't unheard off, and nowadays women have their toy boys too...