The guy had a knife, which might have injured one of the cops, maybe. … they think there might be the slightest minor chance that they could be in a little bit of danger.
I don’t disagree with your overall sentiment that police need better de-escalation training and non-lethal defense weapons - but you need to seriously re-examine your perception of how dangerous a knife attack is. Please don’t trivialize it just to make a point, because it undermines your own credibility and weakens your otherwise reasonable argument.