Hi guys, Haven't been on the forums in ages anyway this my speculation of the story of Machine for pigs.
Basically Mandus encountered one of the Orbs in the temple and was exposed to the images showcasing the future - what will start in the coming century. Two World Wars, Hitler(references to gassing, "making the pigs out us all"), creation of atom bomb, etc.Orb obviously drove him insane, as we know Orbs do and he gained a split personality sort of deal. The Other "Mandus" the byproduct of the Orb, wanted to convert humanity into docile pigmen, to prevent those horrors.
In the ending credits there were some interesting words spoken
"When the lights were nearly all extinguished, we heard in the silent distance, the ManPigs singing to one another.Then as the lights were gone, and we lay together in the deep, they drifted away and all was silent. Such a silent I have never known. And as the dust settled on my open eyes and we lay together embraced forever, I heard, miles above us, the sound of the city turning over in its sleep. A church bell ringing out, and in that moment, the new century was born."
Really interesting and also the last line is referring to the new century which means the start of 1900 as all the notes found in the game all lead up to the start of 1900 which is the beginning of the new century.
And in so the reason for creating the Pigs is so then they can stop the man made disasters of the future by creating docile Pigmen. Well that's my opinon.