This is probably from an opinion held by Mossad Ayoob based on the Daniel Bias case, which wasn't a self-defense case. Rather, at best it was a failed attempt to prevent a spouse from committing suicide - at worst, the murder of a spouse.
The problem in this case stemmed from the fact that the reduced-power loads Daniel Bias loaded for his wife did not leave significant powder residue as did the factory loads tested by the prosecution did at the range the defense alleged the incident to have occurred. Lack of powder residue = she couldn't have shot herself, Daniel had to have shot her and from a distance.
Chances are probably fairly high that if you're going to shoot an intruder threatening you, you're not going to wait until you're in wrestling distance from them and you're probably not going to be worried about whether you're going to leave enough powder residue to prove they died from a self-inflicted gunshot.
Ayoob might make a compelling case if you're planning on allowing your suicidal spouse access to firearms, but if you're planning on preventing someone from harming you or your family, arguing that factory loads are more defensible in court is on the paranoid side of things.