The Aussies were beaten 27-19 in Sydney in Round 1 of the Rugby Championship before suffering a 22-0 mauling in Auckland seven days later.
Former Wallaby coaches Alan Jones and John Connolly have called for Deans' immediate resignation but Hansen has refused to jump on that bandwagon.
"Just because Australia aren't winning against us doesn't make Robbie a bad coach," said Hansen, who took over as All Black boss from Graham Henry in December 2011.
"He had a great record with the Crusaders, where he obviously had a really good team.
"I've spent a lot of time coaching with him - he's not a bad coach. Any team that gets his services are going to benefit from it.
"They're still the number two side in the world. He's copping a lot of flak for losing to us, rather than people looking at the bigger picture."
Deans will hope his side can bounce back when they face South Africa in Perth on September 8, with Australian media reporting that he could be sacked if they lose that fixture and then struggle against Argentina the following week.
Hansen admits that his fellow Kiwi will be feeling the pressure, as will the Australian players.
"He's bound to be, he's got to be. I think the players are too," added Hansen.
"They had the same look in their faces. They were flabbergasted - 'where do we go next, what do we do next?'
"It's not a great position to be in when you are like that, because if you've got no answers, you can't actually improve."