[tracker1]

Well, I take a bit of offense to the last statement... in only that JavaScript is just as, or more valid as a server-side language for development as any other scripting language is. The engines themselves tend to be more optimized than alternatives, and combined with NPM/CJS modules a much nicer experience than many of the alternatives.

As to being able to target mobile/desktop, why not? I mean with Cordova and Electron you can target 4+ platforms with minimal code variance. And in most cases the performance is good enough, until you need more. And React-Native can go even further towards native/compiled language performance, with slightly more variance.

Yes, there is more memory and cpu use than alternatives, but there's also a real cost in developer time, and time to launch. In many cases it's the difference between having platform X, or not... the alternative is nothing, not something better in most cases.