"for an application to be truly independent of the frontend and backend the code must be developed in different languages."
Don't bother reading.
Care to expand givan?
If they are truly independent it would not matter what language they were written in.
By imposing a constraint of not the same, that imposes a dependency.
You are so right, it's not even funny :)
The article is a rant that misses the point that MVC is a description of the interaction between abstractions in an application.