User snaps a photo of it with their smartphone. Bitcoin app on phone decodes it, and sends payment to the address specified.
That just shifts costs from the merchant to the buyer, who now has to pay the telco a recurring fee for a cellular data connection.
And no one is doing that now, without bitcoin. This is like trying to include the cost of an electric generating plant in the price of a toaster.
I don't see who would be willing to pay $400 per year to subscribe to 4G just to be able to spend bitcoins.
Because that is the only reason to have portable Internet, of course...
In a similar vein... I still like to use a GUI that lets me see more than one window at a time.
Despite all the trendy claims to the contrary, I do not get confused from it, even when they overlap! I must be some sort of genius. I've also found myself able to click on icons and buttons that are smaller than 1/16th of the screen, navigate drop-down menus and even read text composed of characters less than 80 pixels high. I also possess the superhuman ability to notice interface elements that aren't surrounded by vast, empty space.
Interface designers nowadays are the large oafs stomping on my LEGO Technic to offer me a box of DUPLO.
There are two ways to write error-free programs; only the third one works.