Haddin said Arthur's successor Darren Lehmann has turned Australia's dressing room and demeanour around ahead of Thursday's first Ashes Test against England at the Gabba.
As England shoot for a fourth straight Ashes triumph, Haddin said Arthur, the South African who was Lehmann's predecessor, has a lot to answer for.
"(Mickey) was very, very insecure and that came across in a lot of our selections and our plays, I think, to be perfectly honest," Haddin told reporters.
"I don't think he understood and was secure enough in himself to get us to where we needed to go.
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"Under Darren we've got a clear message of where we want to go and how we're going to get there. He's able to help guys on the way to get to that point."
In a shambolic Test tour of India earlier this year that Australia lost 4-0, Shane Watson, James Pattinson, Mitchell Johnson and Usman Khawaja were all disciplined by Arthur after failing to submit feedback requested by team management.
Haddin went to India as a replacement for injured wicketkeeper Matt Wade and described the mood within the Australia team as uncomfortable and paranoid.
"That wasn't the Australian cricket team that I knew when I flew into Mohali," he said.
"That was a unique situation which in all seriousness I can't really explain. It was uncomfortable, walking into it.
"Guys jumping at shadows and the insecurity around everything that was being done.
"It's just refreshing to get back here now and enjoy the game for what it is -- a great game that's been great for all of us."