Earlier quoted context omitted.
It's unclear which country and which side of the spectrum you're referring to. This is why I like to use science as a guide (not a decision point), for then there is a chance to be self-correcting.
Yes science can be a good guide. The trouble is that some left-wing social movements explicitly reject science (and Enlightenment values in general) as a tool of the oppressor. There are certain things you're not allowed to say regardless of scientific evidence. For one example, look what happened to scientific critics of Lysenkoism. https://en.wikipedia.org/wiki/Lysenkoism#Effects
I have not seen this, at least on a large scale. Are there specific events you are referencing?