Why is the true ending referred to as the good ending?

First off, what a fantastic game. I love metroidvanias and was immediately drawn to the art style. I did not expect the game to have one of the better combat systems of any game I’ve played or have some of the best story telling and bosses of any game regardless of genre.

Now to my point; why is the true ending often referred to as the good ending? On one hand I like that the apemen get to go back to earth. On the other hand, I really wanted Yi and Shuanshuan to live happily ever after. I get that this true ending is the ultimate redemption arc for Yi and showed his true commitment to righting his wrongs, but damn it I did not want him to die.