To be fair, the actual gameplay of Nier was also good, while the background story itself was rather "meh". Fairly par for the course for Nier.
Nier, in a nutshell:
Main Core Story: You are androids trying to take back the planet, ultimately to learn the whole thing was meaningless; that your characters were suffering for essentially no reason: Good existential crisis stuff. Lots of good questions asked.
The awful background story: So a dragon magically came to Tokyo, bringing a world-ending virus. Humanity "transitioned" to androids. (NieR 1); At some point Aliens came with little robot dudes. Humanity and the Aliens are wiped out thousands of years before the game starts, but the androids and robots are still at war. For no real reason. (Nier 2)
What I expected: The heroes were actually the creations of the Aliens all along (Twist), the crude robots the human defense.
What I got: A hot mess where a lot of the conflicts could really have just been talked out.
(Disclaimer: I do like the game very much if you ignore the nonsensical background story/lore; basically anything that happened before the actual in-game story).