From Stuff (will quote because they remove content after a few weeks):
[It's because] New Zealand has the slowest Internet connections in the world, Dating Association chairman Robert Fathers says.
The British Internet dating executive has complained to Telecom NZ that many of his association's member websites were losing millions each month because of slow connections.
Telecom "stands out a mile as the clear winner of the worst Internet provider in the world", Mr Fathers said.
Costly 2Mbit connections were delivering actual Internet speeds equivalent to a 28k modem, and contacting customer support was "like disappearing into a black hole".
Seeing the number of pages loads for some of the dating sites based in New Zealand, it looks like people are not being intimated by these "slow connections".