Its really really not. If thats your sole basis of why BHX should be grown over say, MAN/LPL/EMA/NCL, then I sincerly hope to god you are never let anywhere near the helm of an airport operation!
Please read what I have posted.
They, the London based Government, are coming from the position of travelling to the NEXT large international airport, thats is Birmingham.
Whatever your beliefs, the NW is twice as far away from London than Birmingham.
Also, what position do you hold at MAN?