Elites in general (scientific or otherwise) seem to have a significant built-in bias against genetic explanations (which is usually what is meant by hereditary).

I've seen a lot of speculation as to why this is so, ranging from it being a noble lie justified by supporting democracy or the status quo, to justifying meritocratic systems (despite their aristocratic results), to supporting bigger government (if society's woes are due to environmental factors, then empower the government to forcibly change the environment and create the new Soviet Man!), to simply long-standing instinctive revulsion and disgust stemming from historical discrimination employing genetic rhetoric (eugenics, Nazis, slavery, etc.) and so on.

Possibly this bias is over-determined by multiple factors.