The examples of the shootings used in the article bespeak really bad decision making and unnecessary use of deadly force. Every year we hear reports of innocent persons being shot because of mistaken perceptions. If we just slowed things down there would likely have been a different outcome.
In concealed weapons classes I spend half a day on the laws relating to justifiable use of force. I am astounded at the misconceptions many folks have as to when they can use deadly force, or when they can present a gun. In all of our discussions about calibers and ballistics and shooting skills, I fear we do not spend enough energy on this: We must never forget that pulling that trigger on a human, no matter how right you are, will change your life, forever. And just because you can, doesn't mean you should.
Having a fortified position to retreat to is good advice for the reasons given-provided you have the time to get there. I posit that a person who has trained and is highly proficient with a firearm is confident and far less likely to panic and fire it unnecessarily. But then very few folks outside the gun culture will devote the time to train.
Good solid doors and locks that take a lot of force to breech slows everything down. In a high crime area a bar like a Katy Bar makes your doors like a fortress. I live in hurricane country where many homes have a fortified safe room. If they come for you in your "hard corner", well the author is right, it removes any ambiguity as to their evil intentions.