Location matters for PR purposes, a great team located in the Bay Area will have the same output if located in rural USA, Europe, or Asia. Companies are made by people, not places (unless you're a farmer, but that's a different story entirely).
Given a group of 7 people (posit some great team) their output is the same irrespective of location, sure -- but how did you get those 7 people? If you were in rural USA, your probability of ever having arrived at that situation is already much lower.
If location truly didn't matter, then you'd be able to move your SF team to Iowa and save a lot of money, but that's not going to work.