Ok, I'm good now.
I think there has always been a good practical purpose for warning shots. When you don't want to kill some idiot hot head, a blast can have a serious effect as an attention getter and firmly establish a red-line, if it has been in doubt.
As a legal matter, it is a liability.
And if it is truly time to act, then feeling that you need to give a warning shot is also a liability.
When would I think about giving a warning shot? Angry drunk man that I just fired shows up screaming at my house and waving a baseball bat. As he approaches a shot into the ground might be useful (many variables involved for sure) to sober him up a bit.
I would never tell my wife or daughters to give a warning shot.
I think you have a good point.