Arghh !! You're splitting hairs here. The ultimate use of some of those films and papers is for the hobby or even the livelihood of MANY APUG members. If you read these sentences again:
"Silver is a totally pointless metal. (Okay, it does have some industrial applications — but even there it's generally substitutable. It's pointless, or at least a luxury, for ordinary people.)"
He is suggesting the world wouldn't be all that different without silver. NOT true for MANY APUGgers !!
This is very simply the point I am trying to make, that our world would be very different without silver. (contrary to the author's beliefs)