The only problem is that when the chamber is empty they are truely empty.
To me that is one of the good things about single shots. Once that gun goes off, I know for sure that it is safe. I teach my kids gun safety using single shots then progress to repeaters. I've met some adults who should still be using single shots. They are real careful until after they pull the trigger and then their adrenaline gets the best of them and they tend to forget where that barrel is pointing.
It takes longer to chamber a second shot in a break action, but it is faster to load than most empty bolt actions. I hunt with the rifle empty in my truck. If I see a target while driving through the woods I can stop, get out of the truck and load my rifle faster than my hunting buddies who are still pushing rounds down into the drop box.
One shot is all you get most of the time, and is really all you should need. It helps keep you "honest" when choosing your shot. For protection during a hunt I carry a S&W .357 magnum on my hip so I don't need the extra rounds in the rifle for that.
Just my opinions...