If memory serves me right, Manchester got a head start way back when the National council for Airports disbanded and Airports went totally independent.
The council allocated development monies to airports through an application process. In the last year of it's existence Manchester was allocated nearly all of the pot for its major expansion of the terminal and stands. This gave it a massive advantage that, to be fair, it's not let go......
It will always be ahead of BHX in routes etc. It's pointless entering any war of words on something that just is and will be. However, BHX is a better airport overall In my humble opinion..