Has been revealed why... *SPOILER*
... he "hoarded" these people?
Did he have a known reason why to lock them up and keep them alive?
Or is it just the title that's suggesting he just liked hoarding?
Dunno. It would have been nice if SOME sort of explanation could have been provided for his behaviour.
Also, why did the guy who had escaped go round killing people? Did he think they were on the same side as the psycho who'd put him there? Had imprisonment driven him crazy? You'd think he'd have tried to get them to help him.