You assume that FordAir was reduced because fewer employees needed to travel. My perception is different. Employees still need to travel, but now there are multiple commercial routes that are cheaper for Ford to send employees on than to use a private shuttle. Plus of course, Ford operates with fewer employees these days.
There are no commercial operators into Barrow/Walney, and given the location and demographics of Barrow, there aren't likely to be any. For so long as there's a significant (defence related) shipyard there, the need for travel is likely to continue, hence the shuttle.