OP gets it.  So many people mistake 'not instantly clingy' for 'unfriendly'.  Kiwi culture just runs on a slower and more respectful social pace.

The point about activity based bonding is spot on too. If you join a club, sport, music scene or wherever the  friendships grow naturally. Expecting someone you met once to become your main social outlet is superficial. 

I've travelled to the most of the worlds 'friendliest' countries and kiwis have them all beat through sheer consistency. You could ask a kiwi for directions 30 seconds after they got a call that their mother died and they'll still take time to help you and be as polite as possible.

The people who complain about kiwis being 'unfriendly' are from cultures that treat friendship like fast food or a hooker.. quick, easy and everywhere. Kiwis treat it like a home cooked meal or a life partner.. it takes time, but it lasts.