Deans had his loyal supporters, but even they would have known that a new face was needed.
Many will see the recent heavy loss as the final straw but Deans would have been sacked even if Australia had won the third test and the series.
His failure to get all of the disparate individuals involved in Australian rugby on board - in particular the talented but flawed Quade Cooper - will ultimately cost him his job.
The 53-year-old had six months left on his contract.
Former Australia prop McKenzie's first big task will be to coach Australia against the All Blacks in a Rugby Championship match in Sydney on August 17.
The Australia Rugby Union is said to be keen to act now in order to give McKenzie enough time to mould a team for the 2015 World Cup. The Wallabies' last World Cup ended in a one-sided semifinal defeat at Eden Park at the hands of the All Blacks.
Deans, the former coach of the Crusaders during their golden run of the last decade, appeared to see the writing on the wall after the recent crushing Wallabies' loss. He was non-committal about his future, saying that was a matter for others, but he must have known his days were numbered.
In many respects he has been unlucky. The Wallabies badly missed the physical presence of loose forward Scott Higginbotham during the Lions series and Deans has never had much in the way of front row stocks - hooker Stephen Moore apart. Australia's scrum was torn apart by the Lions at the weekend.
But in several ways he has been his own worst enemy. He has struggled to maintain discipline in his ranks - Cooper, James O'Connor and Kurtley Beale have been frequent miscreants - and he is known as a single-minded and stubborn individual. There isn't a lot of give and take with him - more take it or leave it.
Deans is a complex individual who doesn't have the easy charm of McKenzie. He knows how important public relations is for a sport that doesn't get much traction in Australia, but he couldn't quite connect with the public the way McKenzie will.
For Reds coach McKenzie, who led the franchise to its first and only title in 2011, it is the realisation of a dream. This season he announced he would no longer coach the Queensland franchise. He was linked with the Ireland job but there was no doubt the only role he wanted was Deans'.
Lions coach Warren Gatland, like Deans a New Zealander, said he empathised with the Cantabrian.
"I've got a huge amount of respect for what Robbie's achieved in rugby," he said at the weekend.
"I know it's been really tough for him being here.
"It's tough to have a Kiwi involved coaching an Australian side."
Australian Rugby Union chief executive Bill Pulver said at the weekend he wouldn't rush into a decision about Deans, but after interviews with McKenzie and White he appears to have done exactly that.
Pulver said "there has been a lot of emotion and comment expressed from various areas ... we will not be entering into any speculation or debate on the coaching issue at this stage".
Deans presided over 74 tests since crossing the ditch in 2008, leading the Wallabies to 43 wins, 29 losses and two draws, for a winning tally of 58 per cent.
His record against South Africa was good - nine wins in 14 tests - but he failed to get consistent results against the All Blacks. He managed three wins in 18 attempts. Australia also twice lost to Scotland under him.
He will take stock now, but the former All Black will be back. Deans is said to be a very good coach and his services will be in demand - perhaps in Europe, but not Australia.
