Finally!
Finally I've found a Linux application to see my photos on a map! And it's beautiful, and simple, and under active development.
And it's even supposed to be able to detect faces, but that process is so slow, and can't be paused and restarted later, so I'm not sure how well it works yet.
But oh my, so far I'm very happy with #Fotema. https://github.com/blissd/fotema