Seems like if what the homeowner did was so reckless and dangerous, the police officer would have been warning others to NOT do it, instead of praising the homeowner for his actions.
I don’t think anyone’s claimed there’s a situation where it would be legal to shoot them but not to threaten them, just that in a situation where it would be legal to shoot them (in some states) you wouldn’t have the opportunity to threaten them so it’s irrelevant.
What I’ve been unable to find is any recommendations from legal or weapons experts that one should threaten rather than shoot, and I’m still not clear why you think there would be times it’s legal to threaten to kill someone, but not legal to follow through on that threat.