He insisted inexperience and bad luck were the major reasons for one of the country's most humiliating test series defeats.
Wagner, who claimed 17 wickets in 157.3 gruelling overs, was a rare shining light for the Kiwis who were pummelled by 296, 247 and 279 runs respectively in Perth, Melbourne and Sydney.
"[There's] not really a massive focus on the personal side of things. It's obviously a disappointing tour and the guys are obviously hurting," Wagner said after the Black Caps arrived back in Auckland.
"It's a bitter pill to swallow. Like everyone else, we had high expectations to go over there and do well and compete but we were outplayed in basically every facet of the game.
"It's quite draining and daunting when you play over there. They [Australia] play a tough brand of cricket.
"We kept trying and fighting but at the end of the day it wasn't good enough."
While the Aussies amassed scores in excess of 400 in each of their three first innings, the Black Caps reached 200 only twice — failing to avoid the follow-on even once.
Asked if he felt let down by the batsmen, Wagner said conditions were far more challenging than expected.
"There's a lot of stuff we can look into. The toss played a crucial role, a lot of things went against us.
"They put us under pressure, kept us in the field for long periods and put up big scores and then you're always playing catch-up cricket," Wagner said.
"To play in those conditions, with the bounce in the wickets and the cracks forming in that heat ... some guys have never experienced that before. It's pretty tough. There's nothing about the batters that let us down, it's more an experience thing."
The Black Caps are set for a brief reprieve before a Twenty20, one-day international and test series against cricketing powerhouse India starting on January 24.
"There's some reflecting to do. We'll focus on the things we need to do better ... and being better for longer periods of time. It's not really about a confidence knock. We're still a quality team, we know the sort of cricket we can play. We've still had a pretty good year and there are still plenty of positives to take out of it," Wagner said.
"We kept throwing everything at [Australia] — up until the last test when everyone was sick and it was a pretty tough time. Everyone was still trying to play with a smile on their faces."
