[hapless]

You're free to do exactly that. Nothing stops you from publishing a web browser that renders static HTML. But the only way to include a JS interpreter is to use the Apple-provided WebKit.

Language interpreters are forbidden to download any code from the internet, so you cannot use JS found on a web page in your own interpreter.

[pcwalton]

> Nothing stops you from publishing a web browser that renders static HTML.

That would not remotely be a practical Web browser in 2015.

> Language interpreters are forbidden to download any code from the internet, so you cannot use JS found on a web page in your own interpreter.

Which is a business decision.

I don't understand why this is controversial; it's well-established that many of the iOS restrictions are business-related. Note that I'm not even arguing here that those business-related restrictions are a bad thing.