Vitamin c prevents colds. An orange will never turn its back on you. It doesn't have one. The bright orange color makes simple people happy. If you find yourself with one while bored at work, you can set up some of those little paper cuppies from the water cooler and start bowling.
Oranges never have to worry about priapism.
They prevent cancer, so say orange grower commercials. Every person you have ever looked up to or admired, every one of your heroes has at one time in their life eaten an orange. The peelings provide an cheap alternative to leather body armour for light skirmishes. Nothing bad ever comes out of comes out of Florida. Worms don't take bites out of them.