So there is even more competition from instant armchair collectors. You know who I am talking about. These are the guys that you see at all the ham fest in your area with keys on their table. Some collectors become upset when they see this. But, I submit to you that there is nothing ethically wrong with making a profit on keys.
People buy and sell old cars, old guns, old furniture, old ham gear.
There is nothing sacred about old keys. Most of the disdain for dealers is likely rooted in frustration. If you become frustrated, then walk on by. The dealer has invested his time and his car miles. He got up three hours before sunrise may times to find those keys.