If we didn't find small furry animals cute, then we could kill and eat them without hesitation. It's not as if other animals seem to find small furry animals cute. Like foxes don't find bunnies cute. Like sea lions don't think about baby penguins that way. (Not that penguins have fur as such, but you get the idea.)
Perhaps evolutionists will explain it by saying we only find small furry animals that look most like our own babies cute. We see our own babies as cute since it helps us bond with our own babies which in turn helps us want to raise our own babies rather than toss them aside the moment they're born. However, even if so, why should that apply to babies that aren't our own? It's not as if chimps think of other baby chimps as cute when they kill other baby chimps."