So they mismanage money that isn't theirs. This is a pittance, because every day the British government borrows £500 million. Yes, it is equal to £8.33 per man, woman and child every day in extra debt. About the only significance of this scandal is it has brought politicians into disrepute for how they spend other people's money.
Yet it hasn't changed fundamental opinions on whether such people can be trusted to make decisions on buying healthcare, education, pensions or infrastructure.
Of course it happens in New Zealand too, yet most people still trust them.
Why? Why would you trust a significant number of not particularly clever people to spend between a third and a half of your money buying services from providers you might not choose otherwise? Do you really think you can't do better? Do you really think the private sector would provide something worse?