If it initiated at close quarters bayonets could be more effective than bullets. It would be the last thing the enemy would expect, and the shock value would get the Scotsmen in among the enemy before they could react. Then it would be to close to use rifles - regardless of Hollywood.
Kind of hard to aim when you see a lot of people screaming and running at you with long, pointy things, and the look in their eyes is telling you that they are intent upon killing you.