Why do they write a self-made "MenuItem" class, and do not use the built-in WPF one?

Question

WPF

I was looking for an example of creating a dynamic menu in the WPF MVVM bundle.
Most of the implementations, in the task of building a menu in the examples, are
based on writing their own class "MenuItem"
in different variations, but the essence is the same.
Why doesn't inheritance from the built-in class apply? or creation directly.
What is the secret meaning?

Answer 1

My IMHO, but look for the answer in mvvm, the basic one simply does not support bindings and it is easier for the programmer to write YaLustItem