The England and Wales Cricket Board (ECB) had promised a "thorough review" in the wake of the resounding 4-1 defeat Down Under, a tour plagued by criticisms of sloppy preparation, excessive drinking and selection mistakes.
Captain Ben Stokes was never likely to be removed but the spotlight was on head coach McCullum and managing director Key. However, the governing body has concluded evolution is preferable to swinging the axe.
A 4-0 loss in Australia four years earlier saw both predecessors - Chris Silverwood and Ashley Giles - pay with their jobs and there has been a considerable appetite for similar action among sections of the support.
But ECB chief executive Richard Gould - son of the former Wales and Wimbledon manager Bobby Gould and formerly CEO of Bristol City - insisted football's hire-and-fire culture was not a useful model.
Asked directly about McCullum's position, which sees him earn more than Stg £1million ($A1.9 million) a year and runs for another 18 months, Gould said a lot of consideration had been put in to keeping the same personnel.
"Cricket is a very unique sport in that it takes a team of leadership...it's not like football where there's a single point of failure or success with a manager," he said.
"We do keep a very close eye on all of our supporters ... but we (are not) going to select or deselect management based on a popularity campaign.
"My old man was a football manager: sacking was part of the job. It didn't necessarily do the right thing. Moving people on can sometimes be the easy thing to do. That's not the route that we're going to take.
"What we've seen is a determination from all those involved to adapt and evolve, to understand that there are different ways of doing things.
"We've got a lot of people hurt by what went on during the Ashes, but equally determined to now put things right and looking forward to seeking revenge in 2027."
Stokes subsequently backed the decision in a social media post.
"Being England captain is the greatest honour a player can be given and I do not take it for granted," he wrote.
"It has its highs and it has its lows, it makes you want to smile, it makes you want to cry. It completely and utterly consumes you and feels like it's the only thing in your life at times.
"The last 3 months has without a doubt been the hardest period of my captaincy journey, it's tested me in so many different ways and I'm sure every other captain has gone through this as well.
"Baz, Rob and myself have the passion and desire to take this team forward, we are going to give you everything we have, we know we made mistakes along the way and we have learnt from those mistakes, you learn more from failure than success."
