Clever but a bit lame given the fact that I guarantee your IP address is already analyzed from a bazillion angles (incl. GeoIP) way before it hits the frontend process. Not sure why they can't use that information.
Because that information is not available in standalone frontend component. They would have to make an additional API request to get that when timezone is available locally.
It‘s because i could see your pull request on this globe. If they use GeoIp they tell me where you live. But they use the user suplied location to not tell me any secret i should not know. Its genious!