Because it's a cartoon, they're the protagonists, and the cuteness is supposed to help us like them. Also, notice that the antogonists are keeping theme by being large, scary predators.
Because that's what the people of North Korea are: cute anthropomorphic animals. Haven't you been paying attention? Also, the military forces menacing them in this cartoon are huge villianous bad-asses with laser guns and spiked mace staves and such, a refference to the Western tradition of promoting scary furries into the administrative sections of the armed forces. You'd know these things if you read the newspaper once in a while.
*Waves hands* I didn't expect a translation from anybody, but it sure would be nice to find somebody who knows the language.