Why not inheritance?

[steveklabnik]

@jibal

No, it only signals that GUIs are hard to write given Rust’s constraints. Ralph’s post reiterates something already well known – Rust sharply limits the kinds of designs that can be implemented in it … and that’s not a good feature of a systems programming language. Again, language design should not be based on throwing up road blocks.

C also does not have inheritance, yet many GUI systems are written in C. You can do the exact same stuff in Rust, if you wanted.