It isn’t. Settings > Privacy & Security > Wired Accessories
Set to ask for new accessories or always ask.
I have to warn you, it does get annoying when you plug in your power-only cable and it still nags you with the question. But it does work as intended!
alt Hacker News
I have to warn you, it does get annoying when you plug in your power-only cable and it still nags you with the question. But it does work as intended!