I agree that there's plenty of ignorance on both sides. That's a psychological question of how we uphold our ideologies. The incoherence of conservatism deals with the ideology's content and with its implications. So there's a performative contradiction between awarding conservatism high epistemic status, or deeming it knowledge at all, on the one hand, and conservatism's social Darwinian implications on the other. Implicitly, the conservative adopts humanistic assumptions which make nonsense of conservatism's cynical content. This contradiction is usually only implicit because, as you say, we're often ignorant about why we really hold to our deepest beliefs.
I take a pragmatic view of knowledge, so I agree that there's an agenda in humanism too. I call it the Promethean or Luciferian agenda of humanizing the wilderness, of imposing extensions of our mind and values onto inhuman nature. Empirical knowledge is part of that enterprise.
