I can only speak from my perspective, but the main reason I'd only click on ones that are near me is because I live in NZ, and there is little point me seeing a bunch of jobs in the valley, unless they're big fans of people working from home in vastly differing timezones.
(move to the states you say? I'm not a fan of your bread. Sorry.)
That was a humorous half-truth. The full truth is a lot more complex and rich with personal details that don't need to be shared with people on the Internet.
We could make up lots of good reasons for not moving though. My parents are sick and I need to be near them. My wife / girlfriend / boyfriend / life partner has a job / sick parents / other commitments where I am. The US won't let me into the country for any number of completely idiotic reasons even though I'm not a criminal (visas are hard). I have a personal objection to the TSA. The point is that for a lot of people moving very very far is legitimately either not an option, or not a very good one.
(the humorous half-truth stands though, at least the store bought stuff I've had when I've been over there. Bread should not taste like sugar...)
Yes, really. In a lot of places in the US what passes for bread is like processed cheese - possibly tasty, but a pale facsimile of the real thing.
"Real" bread does exist in the US, though usually only in wealthy communities, and even in those places is considered relatively boutique. Middle America's definition of bread would shock anyone coming from a bread-heavy culture.