Gregory Horror Show/WMG

The Guests ended up at Gregory House because they attempted/committed suicide.

 * Here's what I think happened: Some cultures/religions do believe suicide victims to be "lost souls" and believe they can go to neither Heaven nor Hell... This probably happened to the Guest in the PS 2 game as well, considering that Gregory, when trying to convince you to stay, tells you to remember "that dark night," which is how the First Guest described the day he first entered the hotel.

This is Hotel California
You can always check in, but you can't check out.
 * Actually in Hotel California, you can check out, but you can never leave.

Gregory is a prisoner of the hotel as much as the other guests.

 * Gregory is the manager of the hotel, and it's implied to be something more than an old, smelly rat. He understands what the guests are afraid of really quickly, and will use it to his advantage to psicologically beat them into surrender. Plus, while many other guests are so fixed with their little obsession, he seems much more calm and rational. But he is not immune to what the hotel has to offer: he fell into Catherine's "cures", for istance. Then comes his "family": James, his troublemaker grandson who gives him more than one headache, and his really unbearable mother. And then there is Neko Zombie. Gregory apparently physically tortured him, and he never did something that directly threathening to anybody else; Neko, while holding a grudge against Gregory, apparently doesn't have this as obsession, i.e. his hate against the rat is NOT the reason he is stuck in the Hell Hotel in the first place. Plus, Neko Zombie is one of the few characters to seriously threathen Gregory - he even burned down the hotel! I think that, while Gregory is in charge of the hotel/purgatory, he is still affected by it. Therefore, since the Hotel works on the fears and obsessions of his guests, sometime it arranges things so that Gregory's fears became true. In particular, two of them are especially strong and destructive: the destruction of the hotel, his "playground", and Neko Zombie freeing himself and chasing him down.