I think first of all you have to realistically calculate the cost of building an airport the size of LBA, then add on all the extra costs, eg the road link from the A1, perhaps also the cost to upgrade the nearby rail station, etc etc.
Now how much to upgrade LBA? New road link, rail connection etc, extend the terminal, apron etc.
What will the difference be? Is it worth it? Would it benefit Bradford- after all it is Leeds BRADFORD airport - so how many would be lost to Manchester.
Then when Church Fenton is big enough to compete LBA may well be handling 787 aircraft to Dubai, etc.