If they hadn't, they would have been replaced by the political leaders. Generals don't get to dictate policy. Also, the generals at the time were dealing with

If they hadn't, they would have been replaced by the political leaders. Generals don't get to dictate policy. Also, the generals at the time were dealing with a very new form of warfare they really weren't used to. Basically, I'd say they were mostly incompetent, but it seems like the invention of the machine gun and how it'd radically change infantry warfare was something that took everyone a while to come to grips with. I do wonder why it seemed to take so long for them to adjust their tactics though.