Queensland fruit fly has arrived in Auckland in illegally imported fruit. Each time, biosecurity authorities have undertaken successful eradication but this costs millions of dollars. Home garden fruit will be full of maggots and it will affect lucrative interational horticultural trade (e.g. avocado, feijoa pictured below, tomato, citrus, pears).
Ignoring biosecurity advice will result in a higher cost of fruit, inability to grow fruit organically (will need spray regimes) and a loss of the ability to grow your own healthy fruit at home due to maggot infestation. Never bring fresh fruit to New Zealand!