So I think that this may just be a very good opportunity to help educate people out of those post-modernist leanings.

"You can't reason someone out of a position they didn't reason themselves into." in the sense that it maps to free-floating beliefs, was my first thought when reading this.

Not saying it'd work universally, or even all that widely, but teaching even a few people is a long way from being a bad thing.

But I think you are right about this. Maybe a small group of LW volunteers should try?