Anger is not a response typically accepted as legitimate in today's culture. We're supposed to have a more sophisticated reaction. We should always speak with finesse, devoid of any emotional outburst. To do otherwise is considered taboo and worthy of the label "extremist", so it's believed.
Although I am not one given to anger, I couldn't disagree more. There is a place for righteous indignation as demonstrated by Jesus on occasion. In fact, the absence of such anger can be symptomatic of a relationship with God that has faltered.