Well, if you language works on js interpreter designed for js only, its hard to create very different language, so we fix what we can, hover small it is. For no

Well, if you language works on js interpreter designed for js only, its hard to create very different language, so we fix what we can, hover small it is. For now tools like emscripten are incredibly unpractical and come with high cost that eats most of potential benefits. When we will have webassembly and ability to ignore js entirely, we will probably see explosion of significantly different languages being used. On the backend there is more and more functional ones, and formal verification is slowly getting traction, so probably this will propagate to frontend too.