[tetrep]

Haskell does address it exactly as you say. Functions and values both being expressions is much less complex. As an example, imagine if you couldn't freely substitute 2+2 and 4. Functional languages say those are the same, imperative languages say one is a value and one is a function call.

It's not particularly intuitive if you're not used to high level math or functional programming, but it really is a lot simpler (not that it doesn't have downsides/leaks in the abstraction, but that's another discussion).

[millstone]

I'm not sure that functions alone are sufficient. That's why Haskell supports existential types, and there isn't a convention for distinguishing them so the critique applies.

[cultus]

Existential types are types of values. There is no distinction.

[cultus]

Existential types are types of values.