NEMA'S problem is to some extent geographical.
Whereas BHX is really too close to LHR to be able to sustain the number of long haul services that the UK's second city should, EMA is always under the shadow of BHX as far as European routes are concerned. This has resulted in the airport being unable to sustain business routes at any sort of frequency (CDG / BRU and AMS excepted) and left it chasing the bucket and spade brigade to whom frequency is less important than being able to fall out of bed and on to a plane to Spain.
Add in then the competition on those leisure routes from LBA, HUY, CVT and soon, Finningley and it's quite difficult to see where the pax growth is going to come from.
Good news is that EMA has unrivalled cargo facilities, and for as long as the NIMBYs from Kegworth, Sawley, Breedon and the like don't get the upper hand this is where the airport will really see growth, since BHX is totally inept in the cargo department.