The Rabbi, THANK YOU, SIR for providing a classic example of the flawed reasoning I was talking about. Your notion that bad guys aren't so stupid to lose life preserving skills is a naive assumption that you are gambling on with your life if you encounter one.
How smart or dumb some bad guy is can be completely irrelevant when the bad guy has been so stoned for too long, gone without sleep while being stoned, or is in the middle of a hallucination that his life preserving skills may not get implemented because he no longer has the ability to recognize dangers in a manner that a normal, not stoned, and rational person would be able to recognize them.
Various stimulants, angel dust, and/or other hallucination-inducing chemicals can give a person the sensation or belief that they are super human and in the process, they lose their ability to fear. Some actually materialize super human qualities of strength (ask cops who have wrestled with a person on PCP).
Sure, most of the time the home intruder with which you will be dealing is probably not going to be totally wacked out such that he has lost all control over reality, but some will. The thing is, you don't know which you will be getting, do you?
By analogy, the training of most cops is not sufficient for dealing with highly skilled, overly prepared, or ambush first bad guys. Day in and day out, they typically deal with a lot of punks, crack heads, drunk drivers, etc. Great, so most of the time, they have no trouble remaining in charge and handling situations. Sadly, when they do encounter an opponent that is overly skilled, overly prepared, or who will ambush the cop without provocation, the cops tend to lose out pretty severely even if they are eventually sucessful in the end. A lot of cops get injured, crippled, and/or killed in these sorts of situations.
Bottom line: You can't count on the person invading your home to be scared of you or your noisy shotgun.
Never underestimate your opposition and know that you can't count on your opposition to react in a manner thay YOU think is the proper manner in which to react.