surely if Web Devs tell them to go pound sand, or intentionally break the site when using Google Chrome, and put a message saying, “Go to Firefox / Safari for a better experience”, that will make Google backtrack.

Riiight… User will surely do that instead of simply never visiting your site again.

any sane people would same the same about a map covering the whole world, and yet there is openstreetmap.

No sorry, that’s a completely different amount of data. Look at how large (or rather, how comparatively tiny) the OSM data set is. Now see how much photo data you’d get for that amount.

I’ve traveled quite a lot with my camera, and never thought afterwards “Ah, if only I knew which temperature they were shot at…”

Considering there’s been basically zero implementation at the moment, neither open source nor commercial, there probably is no demand for a feature like this.

This could be as ubiquitous as location and be widely popular.

Could be, but I don’t really see the value compared to location.

Define “up-to-date”?