The problem is that when there are multiple intruders - in this case there were THREE - you have to be able to shoot all three before one of them gets to you. In a small space like an RV when the intruders have already gained entry, you are trying to shoot them in a heightened state of emotions in a tight space. You might get one, but that one may block your ability to get the others quickly. And that can mean you lose the fight. To assume that you are always going to outsmart, outmanuever, outshoot, outfight, etc., the bad guy(s) is dangerous. And unfair to the folks who have had to try and failed - suggesting they were simply not as good as you would have been or they'd be OK.
I assumed the man had been sleeping because they came through the side door and beat him and according to his wife "he never saw it coming". I would guess that most people if awake would see three men walking in to their RV and coming at them.