Lurking do you think that's because Birmingham used to be regarded (and I mean no offence here) as a bit of a dump and so no other area particularly wanted to be a part of it?
I know the London-centric tendency to label everywhere else as a "dump" is certainly a "thing". But my observation is that outside of London, towns and cities seem to have a ludicrous "derby" mentality which means they would rather London won something than a more local town. The example I gave was when rather than join forces, Solihull and Birmingham decided to work on rival - separate - bids. And, as with the UK electoral system - any split in opposition lets the third candidate in.
As I say, that's just an example. Live here long enough, listen to local radio long enough, and you realise that there is a simmering hotbed of local rivalry which to an outsider - particularly a Londoner - is meaningless.
If all it was, was banter and a bit of a laugh, it's of no consequence. But it isn't. It's the divide-and-conquer so beloved of our ruling elite. In this case, by allowing (or perpetuating ? There's one for "conspiracy theories") these rivalries outside London, it means these places will always be second class citizens.
I once worked with a guy who was passionate that he was born in the town that was 10 miles outside Birmingham. Fair enough. We all need that. However, such was his pride that if you were unlucky enough to suggest he came from Birmingham, you would get both barrels for 30 minutes, and be called stupid and ignorant into the bargain. The problem was, unless you were professor Higgins, he sounded exactly like a Brummie. Moreover anyone from outside the region had never heard of Studley (neither had I till I moved to Brum).
We used to have long arguments where he called me stupid for not knowing the difference. Now he may - or may not - have had a point. But to anyone from London, generally north of Watford is a uniform landscape which encompasses "the north". Some (not all) people can understand there's a "Midlands" in between, but that's not guaranteed.
Now you can rail against this all you like. But it's the way it is. And, if you can't beat them, you should join them, rather - and this is how bad things are - than continue a grudge for 30 years, which is what a lot of people in Sandwell do. On local radio phone ins, people are still complaining about the 1974 boundary changes which named Sandwell over more popular possible names (apparently a mayor came from there). It may be important to the 50,000 people locally, but means absolutely nothing to the 15,000,000 people to the south.
I always get shot at this point ... I'm just the messenger. As I said to my colleague, call me what you like, think me ignorant, stupid, or whatever. But the problem is there are millions like me. Against less than a million true "Brummies".
In a country where one in five lives in the SE region, you are never going to win. Add Birmingham to Manchester to Leeds to Liverpool to Newcastle and you still are outnumbered by London - let alone the South East.
My colleague tried to irritate me by calling me a "cockney", because the closest "insult" he could find was to call all Londoners cockneys. The problem was (and he never grasped this) generally, to a Londoner outside London, being called a "cockney" isn't an insult. Whereas to a Solihillian outside Solihull, being called a Brummie is a mortal wound.
Twenty years of living here, and my ear is in, and I generally can pick up Brum, yam-yam, Wolverhampton, Walsall. But the fact some people get riled about the difference between Tipton and Gornal still amazes me.