" EMA is the place to build a proper British hub"
If you are a parcel yes!
To be honest does a metropolis the size of London need another airport? It already has 6 not counting some that pretend to be by having London in front of their name. Do something about the overcapacity first. having 2 of the alliances hubbing at one airport does not help . New York has got it right with 3 airports and I think London could manage with the same.