We Knew There Was A Reason...

That Stormtroopers couldn't hit the broadside of a friggin' Star Destroyer:

In one war-time study, a Brigadier General found that "only 15 to 20 [percent] would take any part with their weapons." And that this was consistently true, "whether the action was spread over a day, or two days, or three." Eighty percent of the soldiers would not fire, due to nothing more than their innate desire to not take a human life. We also know that the vast majority of shots fired in battle, miss.

Yep. They just have the normal human (clone) reaction to shoot wide. Oh yeah and those helmets? They should really forgo them:

That's right: If the Stormtroopers had just taken off their helmets, they would have probably won the war. Especially considering that they're an elite battalion of well-funded techno-warriors, up against a space hillbilly, a gigolo, a pampered socialite and a furry version of Sloth from the Goonies. It all comes down to the basic principle of dehumanization.