Part of the problem is that rationality is a threat to many groups, and they have a tendency to consider rationality to be an ideology, equivocate between "ideology" and "religion", and then pretend that teaching rationality in public school constitutes an establishment of religion. People define their identity in terms of irrational belief systems tend to not like the idea of the next generation being raised to be rational.

Actually those people are probably right when they charge that pushing rationality often goes hand in hand with pushing an ideology.

It's no accident that one of the examples that Eliezer uses is Robert Aumann "scary" Jewish belief in the link.

In the same way on can catch racists via implicit reasoning tests you can probably catch new atheists who push rationality as a means to push an ideology.