Although I suspect that no one will ever admit it, the government transport policy for the Midlands has been for some time, and will be for the forseeable future:
Majority of UK/European schedule services and inter continental pax services will operate from Birmingham.
Freight (UK, European, and inter continental) plus charter and low cost / no frills, some scheduled services, from EMA.
The remainder can go to Coventry, which, given the limited facilities, will not expand upon what it already has without substantial investment.