Why is it harsh to be critical?
Should there only be criticism when there was some form of intent? Who actually intends to have an accident?
Negligence is about failing to take proper care to operate an aircraft, it doesn't require intent.
If anyone fails to do their job properly, for whatever reason, it is still considered negligence, as difficult as that is to swallow.
The families of the deceased won't feel any better because the crew just made a mistake and didn't mean to.