Religious and other dogmas need not make sense. Indeed, they may work better if they are not logical. Logical and useful ideas pop-up independently and spread easily, and widely accepted ideas are not very good badges. You need a unique idea to identify your group. It helps to have a somewhat costly idea as a dogma, because they are hard to fake and hard to deny. People would need to invest in these bad ideas, so they would be less likely to leave the group and confront the sunk cost. Also, it's harder to deny allegiance to the group afterwards, because no one in their right minds would accept an idea that bad for any other reason.

If you have a naive interpretation of the dogma, which regards it as an objective statement about the world, you will tend to question it. When you’re contesting the dogma, people won’t judge your argument on its merits: they will look at it as an in-group power struggle. Either you want to install your own dogma, which makes you a pretender, or you’re accepted a competing dogma, which makes you a traitor. Even if they accept that you just don’t want to yield to the authority behind the dogma, that makes you a rebel. Dogmas are just off-limits to criticism.

Public display of dismissive attitude to your questioning is also important. Taking it into consideration is in itself a form of treason, as it is interpreted as entertaining the option of joining you against the authority. So it’s best to dismiss the heresy quickly and loudly, without thinking about it.

My heretical by LW standards/scary/worst possible world idea on this is that society needs such dogma. It needs it badly, because coordination is hard. Weak evidence in this direction is that no society ever seems to have existed without it.

That's not the scary part. The scary part is that screwy metaphysical entities like say a God here or there or Reincarnation may in fact impose lower costs on a society than a dogmatic adherence to a particular interpretation of say "justice" or "fatherland" or "the dictatorship of the proletariat".

It would seriously suck to live in that world.

Fortunately, being a rock star from Mars, I live in the world of happy dust and goddesses.