To add, front-end developers and other people that learned in Javascript (because a web browser is something everyone has, turns out it's a pretty great runtime environment, has live editing with dev tools, etc. It's honestly a fantastic way to 'get into programming) could write the icky backend code to make their slick websites, SPAs and games have internet-based savestate
but why does that language have to be one as braindead as javascript. path-dependency is the root of all evil.
Because nobody championed another language for the browser.
Good news is we have WASM now, so you can write backend and frontend code in basically whatever language you want.