Why would many duck-typed dynamic programming languages use a class-based approach instead of prototype-based OOP?

Since quite many dynamic programming languages have the feature of duck typing, and they can also open up and modify class or instance methods at anytime (like Ruby and Python), then…

Question 1) What’s the need for a class in a dynamic language? Why is the language designed that way to use a class as some kind of “template” instead of do it the prototype-way and just use an object?

Also JavaScript is prototyped-based, but CoffeeScript (the enhanced version of JavaScript) chooses the class-based way. And it goes the same for Lua (prototyped-based) and MoonScript (class-based). In addition, there’s class in ES 6. So…

Question 2) Is it suggesting that if you try to improve a prototype-based language, among other things, you should change it to class-based? If not, why is it designed that way?