[gpderetta]

nothing is gained by making void a proper bottom type. It would only break existing code. OTOH make void a proper unit type would be backward compatible and actually make the language simpler both from a specification point of view and in practical terms.

[sixfiveotwo]

I didn't mean that it should be made into a bottom type, even though it sort of looks like it on the surface.

I think the original idea was that void meant "unknown", not "empty" or "non-existent": It was all about whether values could be allocated or not (the wart mentioned above). A plain void variable cannot, but a void pointer can be allocated. For functions, they just reused the keyword to mean "no return value" or "no arguments".