adam , 4 hours ago

but humanity is evil too

Emphasis on this. We humans have become Xenophobic Christofascists* turned up to 11. All aliens are bad** and anything against established doctrine is heresy of the highest order. Human labour is essentially free vs the gross expense of materiel so the leadership will think nothing of having entire generations of a planet mine out some toxic substance that kills before you age much past the ability to outbreed it.

In short, anyone who claims humans are the good guys, is misguided at best.

*EmperorFascists as the ruler is the Immortal God Emperor. ** Officially, but there exists means and people who can deal a little more diplomatically than with a gun.