It is true that in the military, much shooting is done in semi-auto mode. That said there is a huge difference in the volume of fire that can be generated in full auto vs. semi-auto. Companies like Surefire are now building 100 round magazines that are far more reliable than the Beta mags which weren't much more than a gimmick.

Well, full-auto, for which we generically say "M16", has a certain cachet....