People typically write small, short scripts in bash, not web applications. The same goes for JavaScript, but in reverse. They were designed for different things.
There's nothing about javascript that makes it particularly suited for "web applications". This doesn't seem any more ridiculous than, say, using python or perl.
Being event-driven and simple and hot reloadable and forgiving does make it well suited for the task at hand.
You should really think about why javascript is the de facto standard for web scripting. Other alternatives have appeared but even the likes of Google, which control the entire web stack and can pretty much dictate what the world uses, decided against it.