Why is a Capital Gains Tax such a contentious issue when most other countries have one?

Pretty much every country in the developed world has a Capital Gains Tax, even including the USA. New Zealand also has some of the most expensive housing in the developed world and there's probably a link between these two factors. Surely it would be a no-brainer policy seeming that it hasn't destroyed every other first world nations's economy.

Surely having a capital gains tax should be the standard and not the other way around in New Zealander's minds.