It's interesting because 20 years ago no-one would have said "oh, we don't want to see X incident" in the game. "X incident" being an old-style high shirt front. We saw it as part of a physical game. Now most agree that the really bad incidents are best left in the 80s. Some feel it's gone to far the other way however even this thread shows that the average AFL follower has changed their view on what is acceptable - the standards have gone up.
IMO there's too much hysteria about the recent re-write of the rule. There's no rule that actually says the bump is dead (illegal). "Avoidable" bumps that risk a head or neck injury are dead. Split-second/ no alternative hits will still happen as it's still a contact sport, and always will be.
The last year or so tribunal decisions have reflected (most times) a more common sense approach then the hysteria would make you think. Last year's Showdown I was a good example of the sort of bumps that are OK. And that game happened while the AFL had their current POV on bumps.
How else can you word the rule so that the head and neck are protected? If you leave a "accident" exclusion then every player will simply say it was an accident. No-one will admit they were blatantly charging. Then what? I think the AFL are cuaght between a OHS rock and a legal hard place. Society's changed from 30 years ago.