There are definitely two kinds of buyers in my opinion, cash in hand interested and walk on by lookers. I look at all the guns I can at a show but rarely buy to be honest, maybe 4 guns out of two dozen shows, but I got to work the action on every gun I bought and I cant imagine buying a gun without doing that. I can see why some sellers wouldn't want a gun known to have firing pin issues to be dry fired even a single time. However an exception must be made for a cash in hand buyer with the understanding that if it works it will be bought, otherwise I can always find another example which I can try at least once.
Although online from a manufacturer with a good warranty is different as you get such a deal and you have the warranty so it's not such a big deal to just get a replacement in the rare case of a dud. Not all makers offer this though, and I would never buy a Taurus or other "dubious" brand known for hit or miss quality and bad CS online for example.