His (Degrasse's) point was that when there was a spirit of critical thinking that was permitted, there were great advances in science, whereas when that was stifled (I do believe that the jews did not have such a rigid religiosity enforced upon them) they lost their ability to do good science.

That I think was also the point that Dawkins was trying to make.

It is very likely and probable that socio-economic status is a causal factor, however the point being made is not that that is untrue, it is that there is another one of (likely) equal importance.