His focus was not just on winning games, scrambling for results, getting the job done whatever it takes.

His aim was to bring about a huge change in Australian soccer culture.

He wanted to recast the Socceroos as not just a team that was difficult to beat, a side that was collectively more than the sum of its parts, more than an outfit that could fulfil the role of plucky longshot punching above its weight.

It was, and remains, a massive task. But Australian football fans were delighted for a number of reasons.

First, one of their own was back in charge of the showcase side. A man who had played the game in this country, who understood its nuances and who passionately believed in Australian players and coaches and their ability to compete with the best.

Second, he wanted to play the game with a recognisably Australian stamp, utilising the pace, power, strength and strong mentality traditionally possessed by Australian teams, and marrying that to a greater tactical awareness, flexibility and skills base.

It was a manifesto that went down brilliantly and spawned a thousand "in Ange We Trust" memes.

Postecoglou was, even back then, a prickly character, a man who didn't suffer fools gladly, who had unshakeable belief in his own philosophy and ideals and a strong conviction that his players could do the job.

In 2015, when he guided the Socceroos to their first major silverware by winning the Asian Cup, those qualities were regarded as a positive trait, his grumpiness even looked on with something approaching endearment.

Postecoglou never changed the script. What he said after the Asian Cup triumph - that he wanted the Socceroos to become the sort of team that would go on to the world stage and face the best nations on an equal footing, with no inferiority complex - was what he was saying the day he got the job.

It's what he's still saying now, despite the disappointment of the failure to ensure automatic World Cup qualification for Russia 2018.

But what was regarded as fixity of purpose then is now seen as inflexibility.

His lofty ambitions for the Socceroos are now seen as hubris.

His tactical switches and formation changes are regarded as naive and wrong-headed.

And his grumpiness, once regarded as a sign of a man who knew his own mind and didn't bother about what others thought, is interpreted as peevishness or an inability to take criticism.

Football Federation Australia has backed Postecoglou as the man to take Australia through the play-off process that will need to be navigated to get to the World Cup - and it is right to do so.

Would anybody else do better at such short notice? It's hard to imagine. He knows the players, they are familiar with his style and approach.

Given the way the qualifying played out, my belief is that Postecoglou failed more through poor luck than judgment.

I know that's an opinion that won't be popular in many quarters, but the temptation to rail against the switch to three at the back as being the reason for the failure is too simplistic.

My (perhaps naive) belief is that the best players Australia have should be professional enough, tactically adept and technically good enough to switch formations without too many problems: when John van 't Schip was coaching Melbourne City in the A-League he had an inferior group of players able to go from 3-4-3 to 4-3-3 several times in one game.

In all the recrimination it's easy to forget that Australia only lost one game in its 10 qualifying matches. Japan lost two, Saudi Arabia lost three.

The Socceroos did what is traditionally needed: picked up points on the road (one win and three draws) and won their home games, where they picked up 13 points out of a possible 15. Since the tactical switch they actually picked up more points (10) than when using a flat back four (9).

Their failure can be sheeted back to the two terrible games against the team that most would regard as the easiest in the group, Thailand.

The 2-2 draw in Bangkok was awful, so Postecoglou can, along with his players, carry the can for that.

But the 2-1 win against Thailand was one of the most absurd games I have seen. When a team has 45 shots, hits the woodwork three times and has the ball cleared off the line and blocked on innumerable occasions, it cannot all be put down to poor coaching: it's the players who failed to take the chances and sheer dumb luck that was a far bigger contributor.

If Postecoglou was the right coach when he was winning, if his ambitions for cultural change then were correct, then not much has changed.

Yes, I sometimes wish he would adapt a more pragmatic approach and park the bus (particularly in Japan) to try to get a result.

But you have to accept the good with the bad. The good has outweighed the bad.

Australia can still qualify. If it doesn't, he will be gone and the critics can have someone else. But Postecoglou deserves the chance to see this thing through.