These stand around and do nothing cops think they dodged a bullet and let the shooter do his thing. It will not be easy to live with that. It is going to eat at them psychologically. It predict a lot of those do nothings cops will commit suicide in the coming days/weeks.
While technically not murder it is tantamount to it. Read Crime and Punishment by Dostoyevsky.
I don't think it will bother the vast majority of them. Law enforcement went wildly downhill when they started receiving all that "scary" tactical gear leftover from the military. But it was all to look tacticool, not for any real use.