I am supposing that the further back in time you go, the more likely it is that simplicity and performance would influence language and compiler design. As opposed to developer experience.
I think this can be supported by the fact that these fancy language features have been successfully implemented for decades and are only now showing up in mainstream languages.
He invented it for algol, a language with sufficient complexity that it was basically impossible to implement. The process of creating c involved stripping off everything but the most necessary features. Null references made it, nullable types likely wouldn't have.
> The process of creating c involved stripping off everything but the most necessary features. Null references made it, nullable types likely wouldn't have.
Nonsense.
The entire point of Hoare's design was to have type safe references, which C pointers most definitely are not. The entire point of references was that they not be pointers.
Not necessarily. If Hoare had not used null references he might have invented nullables to fill the need and others would have replicated that.