Well, the answer some offer is to simply cancel all the gun shows and turn our guns over to the scrappers.
Or, we can take a realistic view of it and accept that no matter what, people WILL make mistakes. We are not perfect. And that is why we do have the 4 Rules, to keep us from making mistakes.
Your decision your choice, but the reality is that the average gun show attendee risked more danger in traffic getting there than walking the aisles. If we take the same attitude about gun shows and negligent discharges then we'd be walking everywhere because we gave up cars the first accident we saw. I don't see too many people doing that. Even the Amish keep driving buggies after tipping one over.
How far do we take this?
It was a bad thing to have happen, the negligent handler shouldn't be let off the hook. But, no matter what, nobody is ever guaranteed a perfectly safe life. Expecting that you can go thru it with no injuries whatsoever is contrary to long term experience. We cannot and will not ever have a perfectly safe life. Cutting yourself off from all known risk? That price is actually too high for most of us.
See you at the next gun show. It will be there next year and most people who were there will be, too. Same as New Yorkers in sight of the Twin Towers. Life goes on.