The "filthy" aspect of the war was the Jєω Commies in the Defense and State Departments and media who sabotaged efforts to assist the CATHOLIC regime of Ngô Đình Diệm.
If I recall correctly this was also the motivation behind Rwanda Genocide. Can't have a Catholic African kingdom so they did what they did.
More on topic...the other things the traps did was tie up the Americans either dying from or disarming their traps and this gave the VC more and more time to do other things. When soldiers were either busy being incapacitated, split up, medics trying to patch them up, or looking for disarming the traps, it allowed a divide and conquer strategem for the VC.