You wonder why they keep doing this? Must never watch Antiques Roadshow or talk to other collectors. I can understand removing dirt and grease. But never remove metal! And of course that is what happens when you shine up a coin.
Same thing goes on with antique fishing tackle (and no doubt other collectibles). There are some expensive early reels made of german silver (white brass). If not messed with, they have a frosty crystal like finish similar to luster on uncirculated coins. But with just a little buffing, their surfaces turn into mirrors that you could shave with.
Amazing how few remain with original surfaces. I keep telling folks you can always polish an item but you can NEVER unpolish it!
Here is a nice one, and one that has been polished. Note the reflection on the polished one. Both are in great condition except for the finish. And while the one in box is more common, because it is "minty" I sold it for ten times more than the other.


