Yep. Japan also screwed China and Korea over. And America threw Japanese-Americans into internment camps and dropped nuclear bombs on civilians because it was impatient for surrender. And China still has over 1400 ballistic missiles aimed at Taiwan.
Don't even get me started on the Europeans and what they did.
It's Hetalia, hon. Canon means ignoring the dark side and making everything light and happy and kawaii.
(I do have to say that modern-day Taiwan has its share of Japanophiles, up to and including our first democratically elected president; and the Jfen seem to be pretty independence-positive as a whole.)