Don't get me wrong, I have many, many fond memories of Pizza Hut. There's one in my neighborhood and my friends and I always went there as kids and teenagers. It was the favourite family hangout for meals after church, too. I remember a number of birthday parties there.
I also remember very vividly how greasy the pizza was, especially the pan pizzas. As a kid I drank that up (not literally!) as part of the whole experience. As I got older, I began to realize just how junky all that grease and salt was, and just developed a personal preference toward better options. I've found a few local pizza places that make delicious pizza (not necessarily any healthier though) and home-made is even better. But I also find I'm eating pizza less, period, in favour of healthier foods.
I also developed a taste for real cheese, not that processed stuff that all fast food places use in their "cheeseburgers" and such. That's why I don't like the stuffed crust, I find it rubbery, not cheese flavoured, and RIDICULOUSLY salty (but then, a lot of American restaurant food is WAY heavy on the salt).
In short: I've outgrown them.