
Well, let me see if I can explain it.  It's similar to collecting coins,
or stamps, or campaign buttons, or coke bottles, or juke boxes, or model
trains, or just about anything else that is collected (and just about
everything is collected).  In all cases, you might consider it something
of an aberration; I mean, what purpose does it serve?  Not much really;
it's just a hobby.  The collector yearns for diversity (not much use in
having TWO of the same thing, except for trading/selling it), historical
significance (this was the thingy used by so-and-so), technical significance
(this is the only one that does such-and-such like this; this is the first
one to do it this way), rarity, and so on.

Some people use their collections, other people do not.  As you state, you
use your collection.  In one sense, this diminishes the value of your
collection as the items suffer wear and exposure.  In another sense, it
can enhance your own enjoyment of your collection.  Some people collect
firearms that they do not use; other people use some or all of the firearms
they collect.  It's just personal preference.

Oops, 'personal preference' ... I guess we're not supposed to have that any
more, are we?