Many members of the New Zealand public share your discomfort with that. It's possible for the full Parliament to vote with only one representative of each party in the chamber. There are usually a few more than that at times when votes are conducted, but it's certainly far from full. It was a difficult transition for members to make around the mid-1990s when this change was made. Many of our members now, 20 years on, haven't known any other system.
With the variety of other obligations that they have, and a system with a very strong party discipline as well, which has been one of the results of the move to our proportional representation system, it would be very rare for backbenchers, for example, to vote contrary to their party, what you might see in some larger parliaments, in parliaments where members are all directly elected and therefore perhaps not so dependent on their party to have their seat.