Why don't more retailers use Apple Pay, other NFC payment systems?

During Apple's second-quarter earnings call with analysts, CEO Tim Cook said Apple Pay had a record billion-plus transactions during that period. In addition, he said, Apple Pay was coming to two big holdouts - the 7-11 and CVS chains. It will also soon be available in Germany. Why don't more retailers offer it? It's not necessarily more expensive, because Apple takes its reported 0.15 percent cut at the bank level, not from the retailer. Merchants do need to invest in terminals that support it, but many of the chip-reading terminals can handle NFC transactions out of the box.