Sorry, I disagree with your friend. A lot of people who think they could shoot an intruder find they can't. Not everyone is cut out for physical conflict, armed or unarmed, period. Nothing you can say will ever change my mind on this, as I've come to this conclusion after years of first had experience.
Perhaps you are right. My own first hand experience is fairly limited.
Perhaps you're right, perhaps not.
Regardless, I think the key point of the article was directed at those men who feel that they must restrict and/or eliminate the 2nd Amendment rights of ALL citizens, based upon their own decision against keeping and bearing arms.
I certainly believe that some number of people might have a "flight" vs "fight" reaction, when confronted with a given situation.
However, I don't believe that such individuals, having failed to "fight" in one situation will forever fail to "fight" in every situation. The intended victim might not fight a robbery, but might fight a brutal attack on a family member.
A most important point, to me, however is that when every citizen has the right to kba, those who would do harm to the innocent citizen doesn't know: a) whether his intended victim is/isn't armed, or b) whether this situation will bring out the "fight" reaction vs the "flight" situation in the intended victim.
[Of course, I hope that an armed citizen would, and by law could, react in the "fight" mode to defend himself, his family, and his property.]