Unreadable? Personally, I think that Lisp has the clearest possible syntax - because it basically doesn't have any. It's just straight ASTs - something that I have to visualize myself in other languages wich have more syntax sugar.
(a b c d)
f x y z
But golergka said that Lisp's syntax is the clearest, not the smallest. And while that's probably something that depends on one's knowledge and past experience, I think there's something to it. The parens mean that it's unambiguous, and there is very little work on the reader's part to figure out where an expression begins and ends.
There's no operator precedence to keep in mind, no special whitespace rules, etc. It's about as minimal as you can get while still being completely explicit about syntactic constructs.
What you have there is loaded with ambiguity that has to be resolved by semantics. And after the dust settles, you're left without variadic functions.
Partial evaluation and currying are very valuable techniques. They are still succinct if there is a visible, explicit partial application operator to denote a function that is constructed by binding arguments around an expression.
The question is, is it the _only_ syntax that Haskell offers and that the full language is built upon?
Basically, f $ x = f x and is applied with lowest operator precedence (0) and is right associative. Therefore, f $ x y $ z = f (x y $ z) = f((x y) z)
f (x y) z