Not to mention that if you posters can't fathom the depth of depravity, stupidity, and overall toughness that some career criminals are capable of, you've led very nice sheltered lives wherever you are.
People commit suicide by cop regularly enough that there is a name for it that every cop has memorized. This is done while looking down the barrel of a gun they know is loaded and is being held by a person who will open fire.
The problem is not that a shotgun racking won't make a guy shart himself and run, but it won't make every burglar do that. The ones that don't run can read you like a scared rabbit because they're predators. If you have the smallest inkling of doubt, they will see it and maybe take their chances. Then your cheshire cat grin at the satisfaction of getting the drop on a guy and then giving away your position, weapon type, gender, size, personality, and other factors will get wiped right off your face.
Not everyone who burgles a home is Jean Valjean looking for a loaf of bread to feed their heart of gold or a cowardly crackhead looking for something worth 5 bucks.