There were three intruders not one. The man was sleeping when they broke in.
I'm sure if you had asked this man days before the attack, he would have said "I would have shot the intruder".
Of course, there would have been two more intruders, but a good gun owner should have no problem shooting them all before they could get him.
I am very sorry this happened to this man and his wife. Hopefully he will recover. And hopefully the three men will be identified and caught.
For the rest of us - good reminder that just parking on a street for the night is not necessarily safe - even in a nice neighborhood, people inside the homes won't hear or see what's going on. In a campground or RV park, someone is more likely to notice.