There are two types of grieving parents:
1. Parents that want their child remembered for making a difference in the world-- proud of their service, their sacrifice, and their cause.
2. Parents that want to claim victim status for having their children killed by senseless acts of someone in authority.
These two states of mind cannot coexist. You're either one or the other. That is how you cope with your grief.
The first type of parent can't stand anyone that denegrates their child's service, their sacrifice, or the cause.
The second type can't stand anyone that takes away from their victim status by justifying the cause.