I cannot remember where I heard it or I’d cite it, but paraphrasing here, “ the untrained and uneducated (in the law) will usually either do a really bad job at self defense or a really good job at committing murder.”The criminals were never going to take classes but an untrained law abiding citizen with a weapon is just as bad. It's not too keep carrying away from citizens; moreso that they receive proper training on when and how to use it. Proper training prevents piss poor performance.
I like the statement because it acknowledges that the untrained can succeed but it also acknowledges that it may not play out the way one hopes in end.