I think the issue here is that it's probably a bad idea to say definitively "I will do something" or "I will not do something." No situation is Black and White. There is no way to prepare for every possible scenario. For me, if I am alone and my family is not with me, it comes down to, "Can I reasonably do something?" If the answer is yes, well, then I'll do something. If the answer is no, well, then that's the answer. If my family is with me, my #1 priority is them. I'm sorry, it sucks that the other people in the mall (in the stated scenario) aren't prepared, but if helping them means putting my family in danger, sorry, I'm saving my family, and I will be able to sleep at night because I was prepared, and my family is alive. Afterall, the reason I carry isn't to protect the public in general, it's to protect myself and my family. If I can help protect the public reasonably, I'll do so. But if I can't? Well, it's a shame that current society demonizes guns, and the idea of self defense so much that very few people prepare for it. That's not my problem.
After you visit your murdered family at the morgue, do you then confront all those concealed carrying law abiding citizens who let your family be slaughtered and shake their hands and tell them what a good job they did, because you would have done the same thing and let their families be slaughtered in the same circumstances.
This is a straw man, and you're making an appeal to emotion. As a responsible CCW holder, I am well aware of the responsibilities of carrying a firearm. I'm well aware of all the decisions that have to be made. Will I be sad in this circumstance? Of course I will. Will I tell the people who could have done something they did a good job? No, of course not. Chances are, I probably won't even know who they are. Will I blame them for what happened? Hell no. It was a crazy person who decided they wanted to commit mass murder.
You're trying to guilt people into acting when it might not be the best thing to do. If I am alone, I also have to think about the impact MY death might have on my family. That will be one less income, my kids won't have a father anymore, and my wife won't have a husband. Chances are, if I could, I would take a personal risk to help others...within reason. But I'm not going on a suicide mission to save the sheeple who think guns are evil, and that the police and mall cops will protect them.
In essence, I have to look at it the other way. What about my wife and kids looking over MY body at the morgue? Will they think I'm a hero? Possibly. But being a hero doesn't pay the bills. It doesn't give my wife and kids a husband and father. My wife has to figure out how to pay for the house payment without my income. My wife is going to have to try to teach my son how to throw and catch a baseball. My daughter won't have a father to dance with at her wedding. My son won't have a father to cheer for him at the homecoming game. That's the other side of this coin. There, I made your same argument from the other side. It goes both ways. That's why this is such a complicated issue, and bringing emotion into just doesn't work.