There’s nothing incredible here.

All over the world there are places of worship where those who do not adhere to the religion are not allowed to enter. Or no men. Or no women. Or not in a group. (Islam isn’t unique in this, and many mosques are in fact open to all.)

Accept it and respect it. Enjoy a different culture for what it is – don’t judge it by what you think it should be or you’ll be sorely disappointed and better off staying at home instead of traveling.