M-JCS, two things, no one has suggested a second runway at LCY and secondly the UK is a free market not a planned Soviet economy. There are buckets of capacity in the UK but not where the pressing need is.
London as a global city is not helped by more capacity in Birmingham, in a global competition with FRA/CDG/AMS, the market won't tolerate that. There is no direct link between capcity "over there" and a pressing need "over here". Pulpits are for the pub, there's got to be a rationale and a business case for having something.