[stevenwoo]

Don't most humans find most baby mammals cute? We could speculate maybe there's some evolutionary reason that mammal babies are cute to other mammals (for which they are not prey animals).

http://www.bbc.co.uk/guides/zc8bgk7

[sandworm101]

Maybe us finding them all cute comes from our adaptation to find puppies cute. Our willingness to protect baby mammals might have first appeared re wolves, then allowing us to start domesticating others too.