Truly spicy food has typically been found only in the tropics ... and Korea. Chili peppers are strictly new world, but people in eg India/China used other piquant ingredients before the Portuguese introduced them. I have never seen a cogent explanation for the distribution of piquant cuisines.
Until very recently, mostly everyone has been a vegetarian so I don't believe your meat proposal is the whole story. Having said that, Indian not only differs from French food in terms of spiciness. As the article points out, Indian food has a much wider range of seemingly uncomplimentary flavors - recipes are typically a couple of dozen ingredients which is uncommon in the West.