The outrage is the instant assumption by the old media talking heads that US soldiers are damaged goods who are just waiting to snap and open fire on somebody. This has been part of the leftist anti-military template for decades. It was, and is a vicious lie.
Sadly, I must disagree with you. The assumption is not entirely unfounded. Locally, several soldiers from the same unit at Ft. Carson have been arrested for committing a several murders over the past couple of years.
From this article: "Falu-Vives served in Iraq with the 4th Brigade Combat Team, which came to symbolize the problems veterans experienced after returning home from war. Ten of its infantrymen have been arrested and accused of murder, attempted murder or manslaughter since 2006. Others have committed suicide, or tried to."
I don't think this phenomenon is isolated to Ft. Carson, either.