You Cannot Think Those Thoughts!
Our intention is not to argue that Buddhists are angry, violent people—but rather that Buddhists are people, and thus share the same human spectrum of emotions, which includes the penchant for violence.
Setting immigrant Buddhism (Japanese, Vietnamese, etc.) aside, most Americans' view of the Buddhism comes from intellectuals like D.T. Suzuki or various elite teachers, roshis, etc.
We Americans never saw Buddhism(s) in its original cultural contexts.
As I recall, some medieval Japanese monasteries used to send out armed monks to fight in various political struggles, just to name one instance.