I always figured the "mask the rot" explanation was another smug myth to put the past in its place.
(From 2001; I haven't looked for more recent work.)
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.
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 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.