It's all in context. The situation surrounding the ND matters, IMO.
Some dude touching off his Ruger into his stove at night because he didn't take two seconds to check his gun is different than a dude launching one into the dirt when he is stressed from a shooting drill. One is a complete and utter disregard for safety, and the other is generally a setting of a dude trying to better himself, and usually only breaking one of the safety rules at a time.
I dropped a loaded gun last summer for the first time. I was on the range working weak hand draws and it slipped out of my hand. I let it fall as I had planned on (but never knew what I would really do until it happened). I think this is different than dropping a gun at home while you are air gunning the laundry room and bumped into a shelf (don't act like you haven't done it).
One is an honest mistake in a learning environment, one is fucking around. Both can be dangerous, but there is risk in everything we do. Spending hours behind a gun only increases the chances for honest mistakes, which means we need to keep the stupid ones from happening that much more.
One of the more prolific ND's on the net (Haley) was handled terribly by all sides. It could have easily been prevented, the footage could have easily been deleted, and he (or his "team") could have handled the fallout much better. Just because it was on a range doesn't mean it wasn't stupid.
Just my take.