You're implying this happened to JS because of some merit. But it didn't, it was just sheer coincidence and bad luck (for most of us at least, including users).
Also, I disagree that users are suffering as a result, but that is a different discussion altogether.
I believe JS came here because it actually is the best language we have had in the web. It's so easy to throw shit arround, but let's be honest with ourselves, this isn't purely out of luck.
Today, Javascript is sooo interwoven with the DOM in browsers that it is near impossible to separate them. Google planned to do this for Dart, but gave up. If they had done this and other browser vendors had followed, adding a third and forth and more languages would have been (relatively) easy, because the abstraction were in place. Then we would have seen a healthy competition.
There is asm.js. Maybe we will get a "web bytecode" at some point, but that will easily take a decade and more. The pressure is increasing, because our CPUs don't get exponentially more powerful anymore. And delivering apps via the web is still going strong.
Unfortunately there wasn't a good way for the other browsers to implement it. Or perhaps fortunately, depending on your point of view…
Dart was never going to make it, and adding 3 or 4 VMs with their own GCs is even less plausible.
2. See https://github.com/WebAssembly for progress on what asm.js showed was possible: a 2nd, initially co-expressive with asm.js, eventually more expressive, binary syntax for the Web. It's happening now, this year and probably shipping experimentally in 1Q2017.
Writing "easily take a decade" out of ignorance just says to me you didn't even bother to use google!
It's pretty much the textbook instance of a compromise between vendors of competing interests to further the common web. Despite this, it took a really, really long time -- almost ten years -- for JS to receive additional browser-implemented APIs that brought that platform's capability to what we know today and comparable to that of what we had with plugins -- and still, not every vendor supports every spec yet, making this "open web" no less subject to vendor pressures, despite being 'open' and 'neutral' [1].
It is the only language we have had in the web (modulo some minor experiments). The only reason it's popular in the browser is because it's the only choice at all. The only reason it is used on the server is because some folks are familiar with it from using (overusing IMHO, but that's a different rant) it in the browser and are not familiar with the advantages of using any other language.
I've written this before, but sometimes in my most morose moment I like to imagine what the world might have been like had Brendan Eich been permitted to implement a Scheme instead. And I don't even like Scheme!