On one hand I feel the same way but on the other hand when I am looking for that last elusive part to restore a rifle, I certainly appreciate what has been offered to me on e-Bay.

It is a pet peeve of mine as well, I find it a shame. But, like mnay others, I need the parts I need and find it hard to let it slip by. The gun has already been destroyed with little chance of it ever seeing all of it's original parts again. I was given a converted Sharps barreled action as a gift a few years ago. I called the dealer who had it as he had other sharps parts for sale. I asked if they came from the gun, he said they did. I bought everything he had. Sadly, the gun was pretty well striped before he got it. 
I aslo have a weakness for guitars. I don't play much, but love the variety and craftsmanship much like I do guns. You see the same thing with guitars. People will strip 'em down and parts the heck out of them. Same with old motorcycles. My little Harley is a conglomeration of about 50 different bikes, and it still isn't complete. Guys will take a near intact bike that simply needs restored and parts the heck out of it for profit. But again, when you need the part.......
MerwinBray

It's  a crime but often done by many in the trade.   I had a nice Trapdoor carbine. Very late production, one of the carbines made up  by Springfield arsenal to get rid of surplus parts after the Kraig Rifle was in production.

I had it listed with a good consignement dealer for over a year at a fair price. No takers. He asked me several times if I would break it for parts and get half again more than my asking price. I finaly sold it as a whole gun, And I don't think it was broken down but you never know

Boats