Malodery is showing her/his/its ignorance.
One does not have to penetrate body armour in order to stop a confrontation.
An unexpected center of mass hit on a "bullet proof" vest will often convince an amateur that continuing their behavior is not in their best interest.
A law abiding, trained citizen with a legal weapon firing back at someone is enough to change the situation for the better in many cases. I would want that option if I was in a situation such as occurred in Aurora.
If you dont' believe this, I challenge you to meet me out at Weise's Slough wearing your body armour.
There is no body armour involved, but here is an example of what happens to perps when they get unexpected armed resistance. Note how the "situation" changes instantly. The old geezer that stood up for all those in the cafe was using a .380 handgun which is a rather mild caliber and not normally fatal unless one is lucky enough to get a head shot. I submit that even if the two perps were wearing body armor, they still would have skeedadled.
http://www.youtube.com/watch?v=RYA78ss-B-o