These guys seem very similar to the amazing street photographers in Havana. They too use hand-made box cameras complete with little trays of developer, fix, and squares of photo paper...best dollar I ever spent down there.
Well, if Afghanistan had been anything close to a "normal" country, with which I mean a relative peaceful and hospitable place to visit, it is clear these photographers would never have run out of business. A steady stream of tourists visiting the capital would keep the business going indefinitely.
What tourist wouldn't have liked to have his picture taken by such a retro-style photographer with these beautiful cameras?... The photographers would be part of the local custom, an interesting thing to take pictures of, and take souvenirs from, just like a Dutch windmill, or Russian Matryoshka doll.
Now, for the Afghans themselves struggling to survive and make up for decades of war, it's just another piece of ballast to get rid off..