> the programmer can't tell if the program is actually

What do you mean, "can't tell"? If I see this in Python

    (A)(B)(C)

how do I know which of your 9 it means? Well, I'm a Python programmer so I know that it means

    A(B)(C)

which is the function A applied to B, which returns a function that gets applied to C. If you're a Haskell programmer you know that it means the same thing.

I grant you that it is odd to those who are unfamiliar and it took me quite a while to get used to it, but it's much better to write that way in Haskell when writing programs that use higher-order functions.