My cats eat most anything too because they are used to me giving them something, and they assume its good because its a human hand-out. I'm not sure they were meant to eat fruit however.
In their natural habitat or feral life, they would never eat it. They will eat grass however, but the big cats, wolves, etc all eat meat. If your dog was feral, would he climb trees and eat bananas or eat a road carcass? My bet is roadkill. I'm wondering too how efficient a short digestive track would be able to assimilate fruits in a dog.
Not meant to discourage you however, just some thoughts. Cool pictures!