While what you say, Mr. James K., is correct, there was a certain resistance to machine guns (and later, sub-machine guns) because it was believed they wasted ammunition and that they had got by without them just fine. Of course, not everyone believed that.
Whether or not it was being wasted is one thing. But whether or not you can keep up with the ammuntion being expended is another. There were places during WWII (I wasn't there, you understand) where ammunition resupply was partly by mule. German mountain troops fighting in the Caucuses (against Caucasians, I assume) had to make do with mules, sometimes. There were no paved roads and vehicles when present would have to go through mud up to their axles. For machine guns in particular, and German machine guns could go through a lot of ammo real fast, it was a question of fire discipline.
At the time of the Krag, volley fire was still an infantry tactic.
Shoot low, sheriff. They're riding Shetlands!
Underneath the starry flag, civilize 'em with a Krag,
and return us to our own beloved homes!
Buy War Bonds.