I believe proper gun safety teaches people to treat every gun as loaded and safety off. Same reason it’s extremely unsafe to point a supposedly empty gun at someone.
‘Never point any firearm at anything you are not intending to destroy’ is like rule one of any gun range or weapons safety course.
This is taught not only to instill fear and respect, but because weapon malfunctions and user errors happen, and they maim and kill people.
I have had squib rounds on the range, and shitty .22 ammo go off 4 seconds after i pulled the trigger. Had I just assumed it was immediately a dud and gone to clear it without waiting, I could have shot the person in the next stall.