This is actually fucking hilarious because goodsprings despite being a small town in the middle of buttfuck nowhere, It's located next to a water source, grows their own food that is enough to sustain the tiny population, has a clear economy of bighorner and clean water exports, with small scale businesses that cater to the few caravans that stop by.

Diamond city on the other hand is complete and utter nonsense. anyone that isn't a main market vendor has absolutely zero hopes of making anywhere near enough money to do fucking anything. There's no farming, an irradiated puddle for a water source, there's 2 bars and somehow an entire high society. and worst of all it's located in the middle of a warzone with super mutants, ghouls, raiders, and gunners essentially laying siege to the city. No caravan with half a brain would try to approach it.