I would have expected that critical thinking and analysis of source to be a big thing. We start it in primary in ict, but to be honest it's probably a bit early for them to really comprehend it.
This may be part of the problem. People sometimes seem to think that by pushing skills down to a lower level, the kids will learn them better, but what more often happens is that it displaces other more foundational skills, and they aren't able to really understand the higher level skills.
Bias isn't actually that difficult to understand if you are old enough. But to me it's telling that for many, the assumption is that one side is biased, or biased in the wrong way. It's not really about the distortions of viewpoint which are universal. Understanding that requires some ability to abstract however, and insight into one's own thinking processes, the ability to stand outside them to some extent. That's higher order thinking - not the highest, but not for ten year olds.
But I think the other element is that if you want to really teach and allow critical thinking, there is a real possibility that a student will come to a conclusion other than the one you want them to. Maybe about racism, or sex, or same-sex marriage, or anti-semitism, or some other hot-button topic.
People are scared of that possibility which is in itself revealing - they think that reason is dangerous.