I was thinking the usage of spicy spices was correlated to the heat of the country in order to sanitize the meat you eat. (Raw meat in hot envirnoment is the recipe for food indigestion, spices mitigate that.) It's more related to bacteria risks than social factors or west/east. For example, in French cuisine, a steak tartare (raw beef) will have more spicy spices then a regular curry. I believe the whole premise of this article is just wrong.
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.
I once read how strong spices were one of the few techniques available to keep rotting meat edible for a little longer, before the advent of refrigeration. Otherwise, it was salting, drying, etc. to keep meat edible.
India still has the largest population of vegetarians. Today, even in big cities, you will have trouble finding a house on rent if you tell land lord that you are a non vegetarian. Similarly alcohol has a very poor history in India since it was ruled by Muslims for several centuries before the British Raj. Salting and drying are indeed used, in as much as pickles involve it. But meat doesn't come onto picture at all. Spices themselves are dried and don't go bad. Extremely spicy food doesn't too. Warmer climate + fertile gangatic planes also lend themselves to widespread farming.
In contrast, Europe had to import spices and thus the common people didn't have access to spices. Cold weather also pushes people towards hunting by making farming difficult. Obvious outcome is potato, making beer from potato, eating meat, drying meat (steaks).
I have seen that hypothesis in two other comments as well, but I seriously doubt the focus on meat.
I have read before that spicy food in general is slower to spoil, because of the antibacterial properties of many spices. Especially in warm and humid climates, there is much to be said for food that you can still eat the day after cooking, without getting stomach cramps. No matter if it contains meat or not.
