I've kept most of what I've bought but I battle inside myself all the time between practicality and sentimentality. I know what guns I'll use for hunting, or home defense, or SHTF, but there are the others that will never likely serve any purpose other than amusement and folly. I've given a few away to deserving folks and don't bat an eye and I keep a strong hold on some that have no familial connections or sentiments value, but rather, they have a long history told by the wear in the checkering and the once-upon-a-bluing that has been made by hunters past. Those guns are your grandpa's rifle. He gone now and I have a few of them. I can't get rid of them for whatever reason.
Then there's the guns I have reloading components for. I can't possibly sell .311 PSP bullets so I have to keep the related rifles. I started my reloading with all of my handgun calibers so none of them can ever go away. I live in NY so it's even more of a PITA to sell a sidearm. Another reason.
Then there's the cost vs value aspect. I am a cheap bastard and I buy EVERYTHING when I can get a deal on it. $20 dollar rifle? Can't get that deal again. Gotta keep it. Paid $200 below the going price? Can't sell that one either. I'll never get that deal again. Paid too much for it. Can't make my money back so can't sell it.
I'm stuck with them unless I really like someone and give one away. The other element in play is my legacy. Who will get my guns? My unborn? The tax collectors? My friends? The river? I want tehm to be appreciate by the next caretaker.
We are all caretakers of these things that outlive us by generations. I'm a fiddle player. My dead Aunt Betty gave me dead Uncle Steve's fiddle. She died a couple of years ago and he died in the Black Forest last century. I am just a caretaker of that fiddle until it goes to another player; like Steve before me. Same with guns.
Treating guns and knives and the like as they are expendable is totally logical. Treating things as if the spirits that live inside them can have any effect on our hunts, luck, honor, or anything makes sense, too. Beauty is in the eye of the beholder.