Nothing strange about that. Younger girls have crushes on their teachers in RL, so there's nothing to 'believe'. Simply CLAMP borrowing from RL & integrating it into their fiction. You merely see what you want & believe it to be 'true'.
But then Americans watch Fox News & believe it's balanced & unbiased journalism. Rednecks watch WWE & believe it's a proper competition. Many Americans believe in 'Invisible Friends'. They believed George W. Bush was a credible president (even voting him in TWICE).
Says it all, really.