The whole idea of Belvita is an on-the-go breakfast solution for people with no time or inclination to sit down and enjoy breakfast, which pretty much puts them in competitions with granola bars, cereals bars, Pop Tarts, and the like. They are apparently quite popular in certain countries in Europe.
With flavors like Chocolate and Brown Sugar, the new Belvita biscuits are even more like eating cookies (albeit nutritionally fortified ones) for breakfast, an idea that I'm sure will appeal to some.