Snowtroopers were a special type of stormtrooper equipped for colder environments, like the planetHoth. They were Hero's of the Empire for defeating the Rebels on Hoth and for having the courage to fight in extreme cold environments. They were in fact a bunch of whiny little pussies, they hated cold and hid behind layers of coats and an internal heating system to keep them warm. With that kind of equipment anyone would be able to defeat the poorly equipped rebels, who did not have layers of coats and internal heating systems in their clothes.
Besides, they didn't really win at Hoth since most of the rebels managed to escape, something which made Darth Vader most displeased with the unit. Which resulted in most of the snowtroopers getting killed during an "unfortunate training accident" shortly after the Battle of Hoth. Not much is known about the accident, the HoloNet News reported the following:
Coruscant - An unfortunate training accident occurred today in the headquarters of the snowtrooper battalion of the Imperial Army on Coruscant. Reports indicate over 2000 snowtroopers were killed in an immense explosion that ripped through their headquarters. The troopers were all gathered at the headquarters to receive a medal for their brave actions during the Battle of Hoth. Our glorious leader, Emperor Palpatine, who was supposed to hand out the medals was not injured in the explosion. Eyewitness reports of a few hundred Royal Guards, our glorious leader's personal body guards and enforcers, storming the headquarters before the explosion and killing all they found inside have confirmed to be false. The explosion was also not caused by any type of orbital bombardment, it has been confirmed to have been caused by an improperly stored thermal detonator, which detonated the headquarters entire armory. The surviving snowtroopers, who are held responsible for this grave violation of Imperial protocol, will be executed by order of our glorious Emperor. We here at the HoloNet will broadcast these executions live tonight at 22:00.