I don't like the idea of eating chemicals and things I don't know.
I don't want to eat excess amounts of sugar, salt and fats (especially bad ones).
I want to feel better (many studies claim eating real foods make many people feel better overall).
I am hoping to lose weight in a healthy way without having to count calories or measure everything out (again many studies claim a healthy real food diet helps people lose weight).
Many food additives have been linked to cancer and other diseases (I don't care if you have to eat a ton of it to get these results, I don't want to eat anything that has a possibility of causing cancer).
I love food, therefore I want to eat tasty, nutritious, filling foods that I enjoy and will fill me up without making me feel ill after eating them.
I love the idea of not having to count anything. I do not need to say I'm finished eating for the day because I am out of daily calories or points, it doesn't matter that I'm still hungry. I don't need to weigh my food or figure out the percentage of fats, carbs and protein in every meal. Eating real foods when I'm hungry is great for me :)
The 100 days of real food site has a great article about processed foods and why to eliminate them:
http://www.100daysofrealfood.com/10-reasons-to-cut-out-processed-food/