There's a clear evolution -- or devolution, depending on how you want to describe it -- of the experience that William has had. It started with nothing but hard work and subservience, and that led him to a certain amount of success, and it even led him to this place where when he did enter the park, he was open to the possibility of a whole other level of joy, which is true love. William was shown this doorway to Shangri-La, and when that doorway shut, it just invalidated everything. It took his perspective, and it just flipped it: "OK, you got here by yourself, and you thought you could share, but you just need to take the power now. You just need to keep the reins in your hand. No one is ever going to help you."
William had witnessed Logan's standard of hierarchy and power, and that there was a gain to be had in that kind of being, without any real kind of moral barometer. And William just makes that shift, and that's what he's able to do. He's able to control his emotions by controlling an entire theme park, an entire corporation, ostensibly. The potential is limitless. And the genesis for all of that, and more, is, "I need to control this girl who destroyed me." How do you do that? Well, I control this park. Well, how do you control the park in a big way? Well, I control this corporation. It's stunning, that level of heartbreak. I've seen it ruin many men and women.