Earlier quoted context omitted.
> Most web developers are comfortable in many languages. Citation needed. Especially the "most" part. I've been web developer for 10 years when iPhone came out. I liked what I saw, so when SDK came out I've learned Objective-C. Then I learned Swift. And because I know both sides all this feature parity talk really makes me sad about ignorant people not even willing to learn. "Walled-garden" has long ago became though…
You know that the need for citation goes both ways and anecdotal evidence isn't a real reference, right? Web developers know at least JS, HTML & CSS. Too many know Ruby, Python and/or PHP. Significant amount of them know C#/Java/Go or something similar. Then there is Typescript, all those compile-to-js languages and so on. I've never ever seen a web developer who could only program in JS. That would be very ridiculou…
And come on, JS is a C-style language. If you know one you know them all.
It's also not a difficult jump to OOP languages; especially now that Java 8 supported lambdas and C# supports async/await. It's hard to learn concepts, not syntax.