He offers criticism based upon a biological outcome to a spiritual practice, he does not need to understand to declare the outcome stupid. The cultural practices are protected from criticism stuff does not fly- less all insanity of the past comes back crawling from the cracks. Cant criticise witch burnings as they are a "cultural" practice..
Human sacrifice, genital mutilation and various forms of slavery have all been excused as a 'spiritual practice'. "Understanding" will not make me go 'oh, sure...now your destructive practice makes total sense...carry on'. Get over yourself.