Actually, I've paid with NFC in plenty of places in Mexico using Samsung Pay: 7-Eleven, Farmacias del Ahorro, Best Buy (RIP), Farmacias Guadalajara, Sams Club, Walmart, Liverpool, and many many smaller businesses with regular POS terminals, as well as the new smartphone connected terminals.
Mexico is more akin to Europe in card technology (we adopted chip+PIN security many years ago while the US was still in signature security). Around 9/10 terminals in Mexico have hardware compatibility with NFC, the hardest thing is to convince the operator (clerk, cashier, waiter...) to first input the transaction so we can use NFC.