For something scripting-only in an application, I could see that. For a contact form on a website, a pop-up of a menu on mobile or a set of controls that are not pop-ups on desktop and are static content in the page? Not so much. There is literally no reason to treat them any different than any other section of a page as the entire concept of them "popping up" flat out does not apply.

But if they're scripting only they shouldn't be static in the markup in the first place, so why waste time giving them a tag? If you're generating them from JS and applying focus, what actual point does it serve to non-visual UA's that setting location.hash for a :target style trigger does not?

But that's where I differ from a lot of folks working in HTML. If something only works when JavaScript is present/enabled/unblocked, I generate it FROM the scripting... since scripting only crap means nothing to users who don't have it enabled client side or have it selectively blocked.