Inter-city rivalries exist more out here than intra-city. Across all of their major sporting franchises, they're used to one team holding a monopoly on merchandising, tickets etc for specific geographic areas.
Expansion has always been done from a financial profitable standpoint, rather than the historic organic growth of football in England.
Hence why a "normal" suggestion in the US is incompatible in the UK. And it isn't necessarily a "stupid bloody Americans" [as may have been interpreted by my initial post] - that's just how sporting teams as businesses operate over here.
It's probably why a club like Wrexham was seen as a good starting point. Why Birmingham [existing as a club having the name of the city] seemed attractive. It can be found on a map.
TL;DR. If you completely disregard 150 years of history, it's a great idea financially. Trouble is, you can't.