You're exactly right that this would be incredibly annoying, but I think that should be the point. 99% of sites have no business accessing a lot of that stuff and popping up warnings every time they try to would make it a whole lot more obvious when a site is taking advantage of your personal data.

Popups like this act kind of like side effect disclaimers in pharmaceutical advertisements. The ad tries to gloss over them as quickly as possible because they're confusing and scary to the potential customers - for good reason! It's annoying to have to hear that list of crazy side effects in every commercial, but it serves a purpose and it would be a mistake to remove it in the name of "convenience".