So, you know that Entities kill humans, so we kill them in return.
But what if I told you that was why the Entities wanted to kill us?
So, let's say that by some random entity or object, the entities gain knowledge of us humans, showing how that instead of striking at one another, they all gang up on us. We have polluted a lot in the Frontrooms and all that vile shit.
That is why they prey on us out of everyone for what once seemed like no reason.
You think that's the whole cake? The cherry on top is my previous theory, and probably some of the most used concepts. That one where the Backrooms is some sort of representation of hell. They do not lash out at us for their sustainment, but so they can have the latter not cut short.
If we were something they didn't know, they would've been the least of our worries.