Why does everyone want to polarize early on?

[Skylord Amaranthine Darkcape]

some people enjoy the sun...
have some yellow bellied fun
some dance under the stars at night
stalk in the bushes when the moon is bright.
they feast on human souls and dwell,
in the darkest moistest dampest wells
they scare your kids in their dreams
they grab your ankle to hear your screams
some are angelic and kind, for they are made of light
they whisper sweet nothings and hug us tight
they are the white paper under the fight

eventually it all fades away
we end and begin a new kind of game