The former Dubbo police inspector who entered Parliament three years earlier had served as hospitality, gaming, racing and arts minister for just six months before vaulting into the top job after Andrew Stoner's sudden resignation.

The appointment saw him take the extra portfolios of tourism and major events, trade and investment and regional infrastructure and services.

The following April, after a reshuffle, Grant took on the roles of minister for justice and police, minister for racing and minister for the arts, while retaining responsibility for gambling and alcohol policy.

All of that on top of his roles as Nationals leader and Deputy Premier. It was more than an armful for even the most experienced of ministers. It soon showed.

As Fairfax Media reported, senior bureaucrats were privately scathing about Grant's ability to get across his brief.

There was also widely reported conflict – denied by Grant – between him as police and justice minister and the Attorney-General, Gabrielle Upton.

Equally as bad were his unhelpful interventions in health policy.

Grant bypassed cabinet to publicly stomp on potential changes to who could access the Medically Supervised Injecting Centre in Kings Cross and a proposal for the testing of illicit drugs at dance parties.

They revealed a man unwilling or incapable of listening to or consulting more experienced political colleagues or health policy experts.

It's unsurprising, then, that it was complaints about this same attitude that lay at the heart of an internal revolt against him by his Nationals colleagues.

It manifested itself in the failure to consult his party room about the decision to ban greyhound racing, but his colleagues say this was just symptomatic of a broader problem.

Grant, no doubt, has his strengths as a minister and with the experience he has gained there's a strong argument he should be retained in cabinet, albeit with a drastically reduced list of portfolios.

But as much as Premier Mike Baird says he is devastated by Grant's decision and praised his loyalty and commitment, his downfall as leader – voluntary but under extreme pressure – can only be good for the NSW government.

When Baird and Grant's replacement get around to a full cabinet reshuffle, they need to take the opportunity to make some major structural changes, particularly to the justice cluster.

The idea that the police and justice minister should be more senior than the attorney-general has been exposed as completely unworkable. It needs to be fixed.

With Grant as leader, this was going to prove difficult as it would have required him to, in effect, sack himself from one or more jobs.

A post-Grant reshuffle will also present the government with a better opportunity to achieve some generational renewal.

There is already pressure for Roads Minister Duncan Gay to step aside to allow someone younger into the cabinet.

Grant would have found it harder to push for this, given Gay was a key part of his leadership group.

The Orange byelection and Grant's resignation caps a horror year for the NSW government.

But Baird will know it also offers a good opportunity to reset for the next election in 2019.