It makes perfect sense when you think about the order of doing name lookup and type checking. In Haskell name lookup happens strictly before type checking. In more conventional 90s languages like C++ that’s obviously impossible because to compile `foo->bar()` the compiler must first know the type of `foo` before it can begin the name lookup for `bar` in the class hierarchy; in fact in C++ `bar(foo)` also requires knowing the type of `foo` before being able to look up `bar` due to the amazing feature of ADL. In Haskell the type checking was meant to be a research playground for new ideas, such as the idea of type classes, so naturally it was a bad idea to couple name lookup with type checking.

I’m not a historian but that’s just my thought.