And why does that mean I shouldn't be able to turn the requests off permanently given it's a dialog I will never say yes to?
Right? And I'd also add that end users should be able to trivially set/override the GPS coordinates returned these location services.
Altruistic use: you could set your desktop to return your precise location, since there is no service that would do so.
For nearly all intents and purposes, that would be an incredibly useful feature in numerous real situations. Using maps? Set it correctly. Looking for good sushi spots near some other location? Set the location. Away from home but want to see local ads when going to {whatever site}? Set it to your home local.
If there is some legally geofenced thing (ex. employment overtime rules that vary by state), I'd argue that such data shouldn't be valid for that use anyway. Just make the user attest to their location and leave it as a legal issue, not a tech issue.
And GPS/Location data *CAN* be overridden today, in some cases trivially. It's just not made readily available to your average user, so they think it's special. IMO, all browsers should have (an optional) title/menu bar button to set your location. It should default to showing the automagic location, whatever it's getting from GPS, or WiFi guessing, or geoIP lookup, or whatever combo thereof, with an option to set a static value and/or pick the location source of your choice, with per-site options as well.