Crunchy Con: Gen. Barrow's lesson in dying

As the Marine manpower chief in 1976, General Barrow was instrumental in drafting reforms designed to end physical abuse and harassment of recruit trainees by drill instructors. The New York Times, quoting military officials, reported in 1979 that the training reforms, which included closer supervision by officers, had worked well.

At the time, the general said the corps would not ease the tough physical conditioning that was a hallmark of Marine boot camps. But he demanded that there be no more "excess stress" on recruits, including "nose-to-nose yelling" by drill sergeants.

So did the change in drilling and boot camp affect the quality of the soldiers that were produced? If not, then is yelling (and worse, profanity and abuse) at least necessary to replicate stressful conditions? This sort of drilling had been adopted in various police academies--a result of being influenced by the military, and having veterans serving as instructors? Was that a mistake? Does the old way of doing things serve only to promote a 2GW mindset? Or is it necessary in order to instill some form of obedience and motivation in the recruits? How did the Prussians and Germans handle boot camp?

Related links:
wiki
Leatherneck - Magazine of the Marines
Gen. Robert H. Barrow General Robert Barrow’s 41 years of service
Death of former Marine Commandant, Gen. Robert H. Barrow
MilitaryPhotos.net