Edit: I do get a reasonable number of cold(ish) recruitment emails, but they mostly seem to be for real jobs. I'm not seriously worried about not receiving lame proposals, although I appreciate the sympathetic thoughts :-)
Some people get a kind of "shocked" look when you tell them the "I could just build this myself, what do I need you for?" line. Of course, I never meant any disrespect (though some did get quite defensive: "You can't just take my idea!"). Most people are simply unaware of what it takes to start a business, much less a tech startup.
Cold-calls don't mean much and you shouldn't take a lack of them to be indicative, especially if you're far away from that scene. Hot girls get a lot of mail on dating sites but it doesn't make their lives easier. Same principle.
To be more general - these "founders" know they have a bigger chance to find a technical-co-founder (I'm using that very liberally) is in a place with lots of programmers.