I like that article, but it all hinges on your defensive situation being caused by assailants who are strangers. I don't have figures but aren't a lot of violent crimes committed by people who knew the victim? It seems to me like if someone you know is determined to attack you, and they know you have a weapon, they will likely plan for that and use it to your disadvantage. Or they will attack you when they know you aren't carrying.
I can count on one hand the number of people who know I conceal carry. If, heaven forbid, I am assaulted by someone who knows me, maybe the fact that they don't know I have a weapon will come to my advantage. Just my $0.02.
How is it them thinking you are a sheep for the slaughter going to be to your advantage? Wouldn't being seen as a harder target be of a better advantage?