It also seems to have the effect of encouraging you to latch on to whatever "truth" you fancy, providing tools to dismiss any contradictions.

I don't quite get how that keeps people from applying those critical tools to their own beliefs, but we certainly see that a lot. People show up with a Gish gallop attack, without considering the sources that they're using for it.

Regardless, the effect is that in a world that has deliberately deprived people of certainty, they'll defend their own personal domains literally to the death.