I remember as a student seeing an Airbus bigwig explain why they created the A380 using a financial diagram : "short couriers costs X€/seat, transatlantic couriers costs Y€/seat and the new A380 will cost Z€/seat" (Z < Y < X of course), disregarding completely the fact that landways needed to be widened/stretched or that airports started to bubble everywhere leading to what we know as the hub-and-spoke model.
In all honesty, I'm pretty sure Airbus exec went with the A380 design as a pissing contest with Boeing.