Leeds Approach... your figures regarding catchment areas regarding NCL and LBA are pure garbage. If a wonderful new airport was built to serve the West Yorkshire catchment area and located anywhere east of Leeds, it would handle far less passengers than LBA does now! Why, because the catchment area would be less than LBAs is now - as western parts, (Bradford and beyond) would fall more within the influence of Manchester. Having worked at LBA for many years, it may surprise you to know that lots of passengers actually come from Lancashire! This is probably more so now with the closure of Blackpool. Look at a map, try seeing beyond your limited Leeds view of the world - you will see that places on the north side of Manchester, are actually within easy striking distance of LBA. I appreciate time travelling is important, but within a 10 mile radius of LBA there are 1 million people. Please advise which spot, anywhere east of Leeds you will find anything like such a catchment? You cannot, because none exist.
Your comparison with NCL is typically rubbish, as their nearest competing airport, is actually LBA - nearly 100 miles away. Whereas LBA has MAN and DSA on their doorstep. Which brings me neatly on to something you always ignore and that is 1st mover advantage. Even if the present crap airport, (yes I totally agree it is crap), had a long runway, a wonderful large terminal, it would still not meet peoples expectations (like yours), as it will always live in the shadow of Manchester, which is larger, has a bigger catchment and has 1st mover advantage.
Perhaps you remember the piss take of LBA by Alan Whicker decades ago, when the runway was still short, who famously said in a very sarcastic tone, that it only has one international carrier and that's Aer Lingus. Well, some things never change.