I think a lot of people would balk at seeing some random small merchant trying to scan their cards on the Square device, since it looks like some random home-made device.

Besides, how much longer will it be valid for? What's the PIN/CHIP roll-out schedule in the US? Here in Canada you can still swipe in a lost of places, but all credit card companies have long ago started swapping out to the new cards. Once that's al done, all magstripe readers will disappear and it will be chip-only at brick and mortar.

Europe is generally at least 10 to 15 years ahead of North America in card banking, so it's generally pointless to try and compare.