I was reading responses to an article describing an officer using force, and I think it's not always anti-gun, but rather anti-use-of-force. They are not okay with use of force until a suspect is in the act of committing deadly or grievous harm to police officers or the public, in their minds escalating or using force is never appropriate. Basically they want officers to be behind the curve, because justice. In the case I was reading, an officer kicked the suspect because he paused when given a command to surrender, and the suspect even admitted afterwards that he was deciding whether he should fight or run. But people ignore the facts and scream "police escalate use of force against unarmed and complaint man," despite the former being irrelevant and the latter being blatantly false.
I wonder how many people would feel the same way if they they saw the Dinkheller video and then had to go tell officers and their families that they're aware of the risk officers take but want them to defend themselves until the other guy starts getting stabby or shooty.
It also doesn't help that people think you can shoot guns out of a suspect's hands or that OC/tasers will magically end a fight with no risk.