As humans we do seem to have a tendency to want an improvement in
everything, when this is a bit over-optimistic. It is all so personal too; some people are predominantly positive, some are negative. To some money is significantly important and they feel that their personal worth is reduced if they take a pay cut. Others have situations in the own country of origin which mean that a move to NZ will by definition be an improvement.
And despite all of these factors, everyone's own moods will vary and some days it will all seem worthwhile, and other days it most definitely won't, and so the danger of listening to other people's opinion is that you have
absolutely no way of knowing their own personal circumstances, motives or mental outlook at the time of voicing the opinion. Most of the time, we don't even know ourselves.
Bottom line is you could pay everyone a six figure income, and some will complain. The sun could shine every day and some will complain. It might rain every day, and some will complain.
Complaints are only thoughts, and not entirely related to the subject about which these people complain. For example, an interesting thread on a controversial forum looking at the negatives about NZ, and specifically that of racism, left me with the distinct impression that the contributors had confused their condemnation of racism (justified) with a condemnation of NZ as a whole (unjustified). The entire thread would give the average reader the feeling that NZ was the problem, and not the attitudes of some individuals who might have lived anywhere.
In summary, NZ isn't one person's experience, or one type of weather, or represented by one person's salary, and if you (anyone reading this) is an objective, adaptable, tolerant and positive thinker then you will enjoy and benefit from most experiences in life. So the ultimate advice is to place more emphasis on improving these traits in yourselves than on taking to heart other's opinions of external factors outside of your control.
Knowledge is power, but knowing about yourself comes first.