Carbohydrates are also the cheapest calories.
Making them at home isn't /really/ an option for me, not unless I want to eat it literally every day. The greens would go bad in about half a week; the other semi-perishable things would need to go shortly after.
It's so much easier to go out and get something fresh and variety from a common kitchen (restaurant) that services many others all day.
However, because carbs are cheap, and because meat is popular, those are the two things every restaurant has a focus and spin on.
Eating healthy is too expensive.
I like fruit salad just fine, but I would consider it more of a dessert.