It's easy to not realize that many European langauges used to be much more diverse. Every area or even town in "Italy" spoke slightly different language. In some cases there really were language gradients, the further away two towns were, the less intelligible their language. Languages were a continuum.

The national project required standardizing one language calling it "Italian". It's part of making one "Italian" people too. There are good reasons that decisions of where language boundaries are -- and what language is spoken how -- become so "political".