There's sadly no room for sentiment as one bad summer can kill an airline
Its not so much about sentiment, but more of adjusting the resources accordingly.
The point I am trying to make is the following:
LHR is comming up to critical mass and BA in particular are looking at spreading their pax between LHR and MAD, but there are so many pax that are comming from the northern end of the UK that, quite frankly dont need to go through LHR if BA opened up a small selection of routes from the likes of MAN. For example, 138000 people flew MAN-LHR-HKG on BA/CX last year with their code sharing. as a full 365 day even split, thats 378 pax per day that are travelling through LHR.
If 1 HKG flight was moved up to LHR, that frees up those pax to go MAN-HKG direct, the old LHR-HKG slots could be used to open up a new needed route from LHR so not only are pax staying with BA/CX, but they will be happier thanks to a direct service and BA gets its much needed expansions and BAA doesnt loose out at the pax/slot void would soon be filled with another route. Win win win for all sides!
Yield wise, say a ticket MAN-LHR-HKG was £500, pax are obviously happy paying this and BA/CX are obviously happy with the returns of this. They could still charge £500 for said ticket MAN-HKG, but lower landing fees and the removal of the need of the MAN-LHR segment means profit per ticket actually increases!
JFK was another example as how many pax are travelling MAN-LHR-NYC that could easily be contained at MAN rather than clog up all the LHR services? AA has shown BA that demand is there (yet BA still refuse to code share on this?)
There would need to be a few routes that could be moved to MAN to make a small hub viable cost wise, otherwise we would just have another issue the same as the BA MAN-JFK route which lost money not because of pax yield/loads, but the sheer cost of operating a stand alone route.
Another benefit of this could be that as more pax can be contained at MAN, this could also free up one or 2 slots from the shuttles, as less pax means less need for them.
So basically, think of it as a river, running from a mountain top to the sea, via a resevoir half way down. At the moment, the resevoir water level is getting higher and higher to the point the dam is going to breach, and quite frankly, the water doesnt need to be there. Its time to dig a secondary channel so that the water can by-pass the resevoir and get to the sea quicker, easier and relieving the stresses on the resevoir. That is the MAN-LHR-XXX situation.