There has seldom if ever a shortage of eager young males prepared to kill and die to preserve the security, comfort and prejudices of their elders, and what you call heroism is just an expression of this simple fact; there is never a scarcity of idiots.
The quote from Iain M. Banks' "Use of Weapons" reflects on the willingness of young men to engage in violence for the sake of their elders. It suggests that throughout history, there has been an abundance of youth ready to kill or sacrifice themselves in order to uphold the status quo, often related to the security and beliefs held by older generations.
This perspective challenges the romanticized notions of heroism, implying that what is often celebrated as bravery may actually stem from a lack of critical thinking. The mention of "idiots" reinforces the idea that these actions are not necessarily noble but are instead driven by a simplistic understanding of duty and loyalty.