Perhaps we tend to collect (or accumulate) things that used to fascinate us when we were young, I remember for instance that when I was a kid I had a grey bakelite squirt pistol in the shape of a Luger, it was my favourite toy gun, too bad that I broke it one Sunday afternoon while playing with my cousin...
Memories of many years ago aside, I truly believe that is the reason why so many of us "baby boomers" are interested in old firearms, but I'm afraid these interests will fade away over the next generations. . .
they'll probably collect old smartphones!