> Your country does.

What do you mean by can't go? People "can't" go to high-school either if they don't get the minimum grades required in elementary school. How does this even relate to the money angle that I'm criticizing?

> So, should we tell them "no" up front?

What do you mean by telling who no up-front? By requiring that you actually have finished high-school math before being accepted for a 4-year math program in uni? That's just common sense.

> You already said that you/your country won't pay much, so why is it wrong for me to express the same sentiment?

Uhm, no? In what way?