Ignoring some techincalities, the normal distribuiton pops up when you add together a bunch of independent random values. So in 50 question exam, I might have a

Ignoring some techincalities, the normal distribuiton pops up when you add together a bunch of independent random values. So in 50 question exam, I might have a probability p of getting any question correct. My final score might be something like the sum of 50 biased coin tosses, which will be approximately normal. I don't think there's any reason to believe that employee scores (out of 100, say) should be normally distributed.