Cardelli's work is actually quite notable in the academic field of programming languages. And it's far from "random" or "arbitrary" given its constraints. It's a rather elegant exposition of OOP semantics.
Let me come at it from another angle. I'm a bit too blunt. I'm not saying people discredit his work. It could be beautiful and elegant. I'm saying his work isn't accepted in the mainstream meaning generally people don't know about it, nor do people study it and contribute to the theory.