I actually live in Nottingham, UK.
Here there's dev meetups, Second Wednesday, Notts Tuesday and probably more regular events I don't even know about.
I've talked and worked with a lot of developers round here now as well as interviewed with a fair few companies and done their technical tests and talked to their lead developers.
A lot of them write better code than I've seen in the github repos of Californian 'rockstars'. And yes, there's plenty of bad code too, out-dated practices, people asking me if I know VB.Net. And yes one of the companies I worked at (oh so briefly) had terrible code.
No different from the Californian mecca I imagine. Do you think that only good developers go to SV. There's no magic forcefield keeping bad developers out of California. In fact because SV is so desperate you might even argue they probably have a lower average standard.
There's plenty of shipping, successful products coming out of this city and successful IT Teams working for other industries. And bad ones.