"Real" soldiers do sometimes use weapon-mounted optics for observation and target ID. They don't always end up shooting the people they're looking at.
Your statement about cops simply reveals your ignorance about law enforcement.
I've yet to hear a vet tell me that's an acceptable crowd control tactic. Not everything the military does is crowd control, and when they engage in crowd control they don't use all of the tactics that an infantryman at the front lines might use.
To put into less hyperbolic context : when a 'target' is standing seven feet from you, you shouldn't need to aim a sniper rifle at them to identify them through its' optics.
That said, using binoculars would convey a much less threatening impression than observing through a weapon-mounted scope. On the other hand, we don't know exactly what the tactical situation was when that sniper was aiming at the crowd. Unless you do, you're not in a position to say whether he should have been aiming at people or not.
Armed forces use scopes to gather information; this is acceptable.
Police under the influence described by the Stanford Prison Experiment (http://en.wikipedia.org/wiki/Stanford_prison_experiment) Aim weapons at civilians to assert dominance that they feel they must exert.
The action is the same, the reasoning is different.