I believe the
* Catalyst is a serial killer
* Reapers are its trophies
* and what the AI utters can't be construed as the truth of what happen as it is clearly delusional and is entirely immersed in its self-created reality.
As for the game, I have read that most new gamers are playing the multiplayer over the single player, and that most of them are moving onto other games with a more varied multiplayer.