Yes, it's strange. Mind you that the several accusations of bias (e.g. https://www.theguardian.com/media/2017/jan/18/bbc-trust-says...) are political and Nadine Dorries' angle is "wokeness", not political party bias.

So I'm assuming it's a way to shift public debate to the "culture war" topic, where people are more emotional, less rational, than say the economy, etc.

This is not just a Dorries thing, she is merely working from the script. I believe that focusing on culture war issues as a front for Tory vote-winning was becoming a key focus under Munira Mirza, and I only expect it to intensify in spite of her departure.