There is something to be said for ubiquity that programmers of other languages just don't get. Ruby might seem like a good idea to put into a browser but it will run slow as shit compared to the javascript engines that are in modern browsers. A lot of development has gone into optimizing javascript engines. Ruby, not so much.
Javascript is also the easiest language to learn, requires no boilerplate, and will run inside any web browser since the mid 90s, and the code you write with it can run instantly in any web browser, no installation required, just a URL to click on. There are so many reasons to learn javascript and develop with it, it is really unique and should remain that way. I'd really rather not go back to the days when there were two front-end languages, or worse, coffeescript.
There is something to be said for ubiquity that programmers of other languages just don't get. Ruby might seem like a good idea to put into a browser but it will run slow as shit compared to the javascript engines that are in modern browsers. A lot of development has gone into optimizing javascript engines. Ruby, not so much.
Javascript is also the easiest language to learn, requires no boilerplate, and will run inside any web browser since the mid 90s, and the code you write with it can run instantly in any web browser, no installation required, just a URL to click on. There are so many reasons to learn javascript and develop with it, it is really unique and should remain that way. I'd really rather not go back to the days when there were two front-end languages, or worse, coffeescript.