The issue is eyes2ey5, what more can Manchester do?
It is already one of the best connected airports on a mixed mode basis. It's connected to heavy rail which is already close to the limits on the section up to Piccadilly, it has a tram service that starts at 3am, national coach services, buses and then directly connected to the motorway network.
The only weak spot really is trains going south, but given how much of a fuss Arriva had to make to get more north wales, just how much fuss will be needed for Southbound trains is anyone's guess, especially as it seems even 4 platforms are very busy.
What else can they do other than subsidise ground transport to make it more attractive?