Of all the niches one might worry JS will/has claimed an unavoidable status.... native mobile app development doesn't seem like it should be high on the list.

Of all the niches one might worry JS will/has claimed an unavoidable status.... native mobile app development doesn't seem like it should be high on the list. Any language with as critical a mass among devs will probably see tools to help people leverage it across different environments, so JS will likely continue to move into and live in all sorts of niches. But it's quite avoidable on the server, desktop, native mobile, embedded, and it's even becoming partially avoidable on the web. You're safe enough that you don't have to make everyone else dislike it in order to not have to touch it.