Why do I still need a PIN?
Not every retailer accepts contactless payments, so there are still going to be times when you're going to have to make payments by swiping or inserting your card into the terminal, then using your PIN. For example, contactless payments have a cap per transaction in New Zealand, so if your transaction is over this amount you will still be asked to enter a PIN. Note that the cap varies in different countries, and can change.
Currently in NZ, the limit caps at $200 for contactless payments.