But its use of structural typing instead of nominative typing effectively means it takes half the compiler assistance you can get out of static type checking and chucks it out the window

It is quite rare for people to use objects in ocaml anyways, so it doesn't matter much.

A language that doesn't do this is a language that can't be taught to understand the difference between 12 meters and 12 Newtons.

Sure it can. Make a type for meters and a type for newtons. Haskell won't think there is a difference between those if you make them both an int either.