I can't take credit for the analogy – it comes from a report released last year by the Centre for Policy Development thinktank – but it's spot on.

After decades of redundancies and outsourcing, the Commonwealth public service is increasingly frail; but still it faces constant claims of being bloated.

Every bureaucracy produces waste and Australia's is no exception. There are too many middle managers and certainly too many consultants, many of whom are paid to do what public servants could do cheaper – if only they hadn't been sacked.

But overall, the APS is considered remarkably efficient and effective; one of the best bureaucracies in the world.

So why then do our politicians sometimes seem hell bent on wrecking it?

It's not just conservative governments that take the axe to the public service – Paul Keating took a few savage swings – but John Howard and Tony Abbott appeared to cut with particular relish.

Abbott cut 15,000 public sector jobs during his brief stint in power, reducing the overall number to 160,000 – about the same as it was 20 years ago, when Australia had 6 million fewer people.

Abbott said it was all about getting the budget back in the black, but in the grand scheme of things the savings were small and largely undone by those ever-rising consultant and contractor costs.

It's a safe bet Abbott was at least partly driven by ideology: delivering "small government" while clearing out and punishing all those Labor voters who supposedly dominate the APS.

Also, it was politically easy. When a government wants to make savings without risking any political skin it will usually do one of two things: cut foreign aid or cut the public service. Conventional wisdom says the Australian people don't care about either.

It's this attitude – exploited by politicians whenever it's convenient – that has allowed the public service to be progressively degraded. And there's increasing evidence that has been bad for Australia.

This month two of the country's most respected public servants, former treasury bosses Ken Henry and Martin Parkinson, made thoughtful and timely interventions on the issue.

Interviewed for the latest Quarterly Essay, they warned the public service is losing its ability to solve complex problems and provide effective advice. That could have devastating long-term effects on the way we're governed.

"Many departments have lost the capacity to develop policy; but not just that, they have lost their memory," Henry said.

Parkinson said junior public servants were missing out on the mentoring they needed to do their jobs effectively because so many experienced senior public servants had gone. That was leading to a decline in the quality of policy advice, to the detriment of good government.

"Becoming an effective policy adviser requires learning by doing under the guidance of experienced hands – an apprenticeship," he said.

"Today, in some institutions, smart people look around at their colleagues and find there's no one to talk to, to learn from, who has experience in delivering real reform."

Abbott controversially sacked Dr Parkinson in 2013 – despite then-treasurer Joe Hockey's objections – reportedly because his chief of staff Peta Credlin thought he was too closely aligned to Labor.

It was a clear, early sign that Abbott didn't have much respect for the professionalism or impartiality of the public service.

Thankfully, the early signs from Malcolm Turnbull are very different.

The worst-kept secret in Canberra right now is that Turnbull will soon appoint Parkinson as secretary of his own department, thereby making him the most senior public servant in the land. He will be a very influential voice in our prime minister's ear.

The appointment sends a clear signal that Turnbull intends to break with the Abbott model of public service engagement – he respects the public service and wants it working for him, not against him.

His public rhetoric has been very different too.

In June this year, a few months before taking the top job, Turnbull told a conference of his concerns about APS outsourcing.

In doing so, he urged a societal rethink of the way we regard and treat public servants.

"What we have to do in government in my view is stop panning public servants and do more to ensure that they do their job better. And one of the ways to do that is to make sure they do the work that is their core responsibility, as opposed to outsourcing everything," he said.

"Talent is the real asset of the Australian public service, so we have got to have a focus on the APS, a respect for the quality and seek to promote and improve the quality of that workforce all the time."

Don't expect a big boost in public service numbers anytime soon – Turnbull is still a believer in cost-effective government and plenty of people in his party would resist any major spending increases. But he does appear to understand that the way to improve the quality of the public service is not by starving it to death.