Sometimes people get really confused about food, specifically something that because a food is calorific that it must be unhealthy. These foods include avocados, peanuts, eggs, cheese, etc.
I read loads of people think that pizza is unhealthy. I can only imagine they mean the take out pizzas that are greasy and full of "melting cheese." I myself make my own dough, my own sauce, load it with veggies, and put fresh mozzarella on it. When it's out of the oven I'm known to load it with fresh basil and an arugula salad right on top. Nothing unhealthy about that.

You're right though, about certain foods. A few years back I use to think peanut butter was unhealthy, or bread.. but really a lot of it is how it's prepared and how much sugar is added to it. The foods alone aren't the problem.