It is an instruction given by Jesus to situations in general so that we can in turn refresh our outlook on life and focus our energies on something other than anger.  If one reacts passively, it is helping yourself from the source of where negative emotions usually arise.  We should remain perspective on a situation and not allow our state be controlled by anger.   

Still, there are situations which call out for defense.  There are situations where we must give answers or explain ouselves.  It's not that we must put all our inner self and emotions (good or bad) altogether in a closet.  Else, it becomes playing out the victims everytime someone is against us.  Example:  If someone should fairly enough criticize me for a wrongdoing, and it happens that I don't like it; should I deceive myself seeing that as an attack, and eventually play out the passive victim?  It wouldn't make any sense at all.  We must not react by staying in a couch for the sake of our safety shield from others, but we must react diligently.