I understand that some countries allow small purchases to be made with special bitcoins made out of atoms and backed by fiat currency. I’m told that in those countries, their atom coins are ubiquitous, and, there is technology that allows mobile payments.

For example, you can purchase foodstuffs from vending machines using atom coins. The mind boggles.

And unlike bitcoins, the atom coins aren't traceable!

However, the wallet technology is extremely insecure.

My wallet could get stolen, with a fraction of my money in it. Seems more likely that bitcoins will get stolen at some point, and all your money is just gone.

Tip: Carry your atom-wallet in your front pocket. Pickpockets have a hard time with front pockets.

This weird technology has been used for some time though, so users have already internalized good practices wrt. secure mattercoin handling.

Well considering the BitCoin hype has died down...that seems unlikely.