Hopefully we're not subsidizing Costa, they should pay the full whack for rent.
I'd probably agree that we don't need an all-singing-all-dancing landside cafe with the size that it is now. A couple of small kiosks offering a different range of drink & food/snacks would probably work.
But I do think that capital expenditure on extending the departure lounge area would be a good move. Could also introduce another drink/food operator to ensure there is at least some competition.
The important thing is, IMHO, we don't need development managers or their ilk to sort out this kind of basic stuff. It's a complete waste of money. All that is required is common sense. Nothing more.