how many millions of Americans have amateur radio sets?
Relatively few people are amateurs these days. My point was only that getting going with ham radio is easier, quicker, more reliable, and far less expensive than setting up the infrastructure for any sort of useful internetworking when you don't have an ISP, much less a backbone of routers, switches, and DNS and BGP servers to interconnect the ISPs or their equivalents on an alternative network.
Have you ever set up a business network for, say, a company of 10 or more users, with a commercial ISP's pipe from the internet? Okay, now you don't have the ISP -- what do you connect to, how do you "tie in" to anyone else's network? The internet is not just a huge collection of "last-mile" connections to consumers and businesses. With all due respect, I get the feeling you're not familiar with what useful internetworking entails, or else you're proposing something insanely crude, like the BBSes and UUCP mail relays of the 1980's. No one today would use that seriously, even in an emergency.
I'm a hobbyist/experimenter/system-designer who got started about 1970 even before there were microprocessors. Yet the idea of designing and building all that from scratch doesn't appeal to me, and it's not for lack of interest in the concept. It's that I know what it takes to make a useful network, having done it on a small scale a few times (I'm a Network Systems Admin by trade these days), and it just ain't gonna happen on a large enough scale to be useful.
Me? I plan to get a ham license.