bmi (Midland) didnt leave BFS because of easy,it was due to the price structure or different prices TBI had with other airlines.
The terminal was not built for bmi it was already there, as they had to extend it for them.
As for on-time stuff,I dont think any of the other London airports come any where close to volume that LHR's amazing controllers handle so the stats are slightly unfair oh and before anyone goes on about "thats why we go to the other airports" you wanna try and get the gatwick express to LHR,I think youd have a hell of a lot more time going direct even with a small(if any) delay.
Rgds K.I.L.