Credit/Debit works best for large companies where there's little to no haggling, and where the sheer volume of transactions allows that merchant to negotiate good terms with the processor, but they're still at the mercy of the processor as far as account and transaction fees are concerned, and then there's the other issue of security. Target, Neiman Marcus, and PF Changs are all going through that right now, and I don't doubt that it'll get worse as time goes on, and while "pin and chip" cards may help, I expect that someone will figure out how to steal through those too, and the cycle will just continue.
And then there's the personal sale angle. I'm not going to take paypal or have the ability to process credit cards for a yard sale or some crap that I'm selling through the classifieds or craigslist. Given how I'm mainly just trying to recoup something in the process of a sale, adding more hoops or steps will just result in my not bothering to sell junk anymore.
And as to your analogy of GPS vs maps, I can use a map without any electrical power, and I can identify on the map, if it's a good one, which roads my low-ground-clearance car can traverse, versus which roads my 2wd small pickup can traverse, versus which "roads" I'll need a 4x4 or truck with significant ground clearance to use. Most of the time the latter aren't even noted on GPS systems.
And that's not even going into the other companies that built personal organizers around this same time.
Geek-chic likes to talk about and to chase the latest gadgets, but the hype really isn't as widespread as reports would indicate, and even those that have chased the newest have often gotten tired of doing it without any real, tangible improvements.
if a human cannot determine if they just got a hummer from a machine or another human?
Gives a whole new meaning to, "My computer went down on me..."
To your other point, I had to do some maintenance on some 10+ year old perl today on a legacy system. I used vim, and while I'd never worked in perl before it was enough like C that I was able to make do. The script just does some network monitoring and presents an up/down list on equipment and is only about 150 lines long and reads from a 1500-entry flat-file, but that I was able to just jump-in and work on it without experience and that it needs little more than mod_perl says a lot for basic, normal-people languages and development environments.