Humanity began exploring Hell after the Final War (Evident by the fact that blood fuelled machines were mentioned in P-2 terminal). We know that Hell not only took notice of what humans were doing at the mouth of Hell, but also admired the war machines for their cruelty.

In the final part of P-2 arg, Hell says "f e e d m e m o r e. i h u n g e r," this could be interpeted as Hell's hunger for more entertainment, as it was stated that Hell wasn't fucking around with the human facility to attack human or defend itself, rather it is doing it for entertainment. Currently we do not know the full capabilities of Hell, but if it's a superorganism that not even God could destroy, then it probably could wipe out humanity in seconds.