But when that language has variadic parameters, you must explicitly invoke the currying to distinguish it from a normal function call that uses up all the variadic parameters (just as you can't specify different types for the variadic parameters). In a language where each function has only one parameter, the currying can be implicit (just as all parameters defined in the program can be statically typed).
I should have written "You can, but..." in front of my comment above because you weren't disagreeing with me. In my original comment I italicized "must be variadic" which was my original emphasis.
But if you eliminate variadicity and macros from a dynamically-typed, strictly evaluated language, you might as well add optional static typing so you can extend that implicit currying into monads, etc.
