Backwards compatibility of programming languages suck

Backwards compatibility in programming languages may not limit the addition of new features, but it does limit the simplicity of the language.

But is it really necessary?

If you write a program with a version of the language 1.1, and then it’s released a new version 1.2 which some things that aren’t backward compatibles, it doesn’t mean that you have to update your code, you can specify the latest version of the programming language.

What are the limitations of this approach for you?