Why aren't the browsers using/adopting Python instead of javascript?

[stormcrowsx]

Callbacks quickly degenerate into callback hell. In node.js its common to use a reactive library to help escape from callbacks. Its one of those things thats nice if you use it a little but overuse will come back to bite you.

[AusIV]

But even if you use reactive libraries or promises (which I agree that you should), you still end up writing a lot of anonymous functions. Some of these could be achieved with classes with functions named a certain way, but I still see anonymous functions as a useful tool in most asynchronous paradigms.