Is this really so?
I have the feeling this is 'popular' because there are no alternatives. Web is popular, this is just an accompanying disaster.
There was an argument about fragmentation so people didn't want more things as option. As an answer to that there were many (?) attempts to solve problems that come with JavaScript for years, anybody remember coffee script? The only one that worked is typescript. And typescript again transpiles to Javascript having worse performance and a bunch of limitations.
The only alternative that I saw that makes sense is dart and people crucified google for considering to include it in chromium. It is really a shame that this didn't get accepted.