With the system in Canada there is always the possibility that someone bugs the Interac reader. Everyone using the machine will have their card number and pin stolen. The perpetrators then usually wait for some time, often years, then make purchases using your account. Waiting makes it more difficult for the police to track down the retailer that had their hardware bugged. Once identified the banks have everyone who used that machine change their pin code to prevent further theft.
This has happened several times in Canada. People have even installed fake bank machines designed for the sole purpose of stealing this information. Interac is great but still a big target for theft.
Apple Pay, and probably Google wallet, prevent this type of attack. Theft becomes a non-issue. So long as you do not have your phone stolen and fingers removed, your money is safe. This is a big improvement over Interac and will save a significant amount of money currently being spent on fraud prevention / compensation.
What we need is competition in this field. Let Apple have their system and let Google do whatever they want. Keep the hardware interface (NFC) standardized so that newer, better systems can be designed. Keep away from proprietary pay terminals. Multiple solutions should work with the available infrastructure thereby limiting the entry barriers when competing in this market. It will be interesting to see what gets developed.