Alonso was handed a post-race drive-through, which was converted into a 20-second penalty, for erratic and potentially dangerous driving in the closing stages of the race at Melbourne's Albert Park.
While duelling with Mercedes driver George Russell, Alonso lifted much earlier in the run up to Turn 6 to get a better exit onto the following DRS straight as he battled to stay ahead against the quicker Mercedes.
Russell was caught out by Alonso's tactic and crashed off in the Aston Martin's dirty air.
Alonso's penalty demoted him from sixth to eighth, which the Spaniard slammed as "disappointing" as "at no point do we want to do anything wrong at these speeds".
Speaking for the first time since the incident, team principal Krack fully backed his driver, saying Alonso "would never put anyone in harm's way".
"Firstly, in motorsport everyone is relieved that George was okay and walked away after his accident," Krack wrote in a statement shared on Aston's social media channels.
"I want you to know that we fully support Fernando. He is the most experienced driver in Formula 1. He has competed in more grands prix than anyone else and has more than 20 years of experience. He is a multiple world champion in multiple categories.
"Fernando is a phenomenal racer and he was using every tool in his toolbox to finish ahead of George - just like we saw in Brazil last year with Sergio [Perez]. This is the art of motorsport at the highest level. He would never put anyone in harm's way."
Aston had 96 hours after the race to request a right of review and appeal the penalty, but it has decided not to do so as that would require significant new evidence which wasn't available at the stewards' meeting.
The relevant evidence was already available at the time, with the stewards poring over Alonso's telemetry.
That showed he lifted off the throttle around 100 metres earlier than on previous laps, tapped the brakes and downshifted, only to accelerate and upshift again as he said he realised he had lifted earlier than necessary to optimise his Turn 6 exit.
It is this "extraordinary" slowing down before his usual braking point that the stewards felt warranted a penalty for "potentially dangerous driving", even if they couldn't determine the Spaniard's intent.
"To receive a 20-second time penalty when there was no contact with the following car has been a bitter pill to swallow, but we have to accept the decision," Krack added. "We made our best case but without new evidence we are unable to request a right of review."
The 96-hour appeal period is a new element in the FIA's International Sporting Code for this year, with teams previously having 14 days to submit a right of review.
