Because of the Implication!

Police are people too, but even on a subconscious level no one in the public is really going to treat them that way. It’s impossible to treat someone who can theoretically decide your fate on a whim as an equal. The badge gives them control over you, to the extent that it’s difficult to even have a casual conversation with them for fear of accidentally revealing something about yourself that you don’t want them to know.

When it comes to de-escalation, it’s even harder, since someone who is in a highly aggressive or stressful situation understands their freedom or even life may be on the line and is that much more likely to act in an irrational way. It’s the same effect you see when you back an animal into a corner. They’ll snap at you and fight for their life even if it’s obvious they won’t come out on top.