Whilst those who understand how an airport operates or are frequent travellers, realise that many parts make up the whole experience, most of those travelling through once or twice a year going on holiday, do not understand this. To them, Manchester Airport is responsible for their good/bad experience and as such its reputation can easily be tarnished. If MAG really care about its reputation, it's important for them to be proactive in making sure the overall experience is good, and not just those parts that they directly profit from.
Many airport operators around the world understand this - MAG should take a look at SIN or HKG and learn from how they operate. Even at peak periods,you rarely wait more than 5 minutes to clear security.