Though it was not their fault they were issued the rifle with inadequate training in maintenance. And a rifle that was quite unlike the Garand, M-1 Carbine, and M-14 in function and cleaning prototcol.
Like most of these things, they started with Germany. “Tiger Feibel” was the cartoon book that taught WWII German tiger operators the tricks to keeping that beast operational.
Army guys laugh at Marines, who won’t use the best training technology.