Former Phoenix Suns player and head coach Ainge stepped into the Jazz role in January, after the side had the best record (52-20) in the Western Conference in 2020-21.
But the Jazz bowed out of the 2021-22 playoffs at the hands of the Dallas Mavericks, after a 49-33 season.
Key players including Rudy Gobert and Donovan Mitchell have since left, along with head coach Quin Snyder who resigned in June, marking a period of change for Utah.
"What I saw during the season was a group of players that really didn't believe in each other," Ainge told reporters on Monday. "Like the whole group, I think they liked each other even more than what was reported, but I'm not sure there was a belief.
"When we got to the playoffs I thought, well this is a team that has had some disappointing playoffs so I thought maybe they're just waiting for the playoffs. I gave them that benefit of the doubt, but it was clear the team didn't perform well in the playoffs again.
"I believe every one of these guys went into every game believing they were going to win, don't get me wrong on that. I'm just saying when adversity hit, the resolve, you could see in a team that has a true belief in having each other's back or one another.
"I think individually they have resolve, but I just don't believe collectively they did. So you see a lot of players trying to do it on their own as the believe in one another wasn't as great as teams I've been on and around that I've seen."
Jazz general manager Justin Zanik claimed that the side's offseason changes, trading out All-Stars Gobert and Mitchell, was about opening up another window to challenge for an NBA title. Lauri Markkanen, Collin Sexton and Ochai Agbaji all joined the Cleveland Cavaliers as part of the Mitchell trade.
"You have these conversations and there's a return and you start balancing what you can acquire on the market for perennial All-Star players, and we traded two of them this summer, that necessitates us to make a decision for the organisation that is hard," Zanik said.
"We've got really good players, but you have a timeline you want to open up with a maximum window.
"Previous results kind of told us who we were. It wasn't just a one-year thing. This was a good three-year period where we won a lot of games and had a lot of success, but we were tapped out from a potential stand point and we needed to reset that."
Danny Ainge has announced he is retiring as president of basketball operations for the Boston Celtics, with head coach Brad Stevens promoted to the role.
Ainge is the only person to win NBA championships as both a player and general manager with the Celtics, who confirmed his departure on Wednesday.
The 62-year-old was at the helm of Boston's last title-winning team, back in 2008, and hired Stevens from Butler University to replace Doc Rivers.
However, after a tough season for the Celtics came to an end with a 4-1 series defeat to the Brooklyn Nets in the first round of the playoffs, Ainge has decided to leave his post.
Stevens, who has been the coach for the past eight seasons, will move up to take over from Ainge in the front office, meaning he will oversee hiring his own replacement to lead the team on the bench.
"Helping guide this organisation has been the thrill of a lifetime, and having worked side-by-side with him since he's been here, I know we couldn't be in better hands than with Brad guiding the team going forward," said Ainge in a statement released by the Celtics.
"I'm grateful to ownership, all of my Celtics colleagues, and the best fans in basketball for being part of the journey."
During Ainge's 18-year stint managing the Celtics, Boston made 15 playoff appearances and reached the Eastern Conference Finals seven times.
Their championship triumph in 2008 was one of two trips to the NBA Finals, while it was their first title since 1986. Since that successful season, Boston have won more playoff games than any other NBA franchise.
Danny Ainge announced today that he is retiring from his role as President of Basketball Operations. Brad Stevens has been promoted to the team’s President of Basketball Operations.https://t.co/XfGfMVkMkq
— Boston Celtics (@celtics) June 2, 2021
The former Utah Jazz guard and three-time All-Star was part of arguably the biggest trade of the offseason, with the Jazz receiving three unprotected first-round picks.
They include two future first-round pick swaps in guard Collin Sexton and stretch forward Lauri Markkanen, as well as Ochai Agbaji, the 14th selection from this year's NBA Draft.
Mitchell had been one of the most desirable names on the market after it became clear the Jazz were entering a rebuild following their trade of three-time Defensive Player of the Year Rudy Gobert to the Minnesota Timberwolves.
Despite being "excited" to be in Cleveland, Mitchell – who is from New York – told ESPN he was close to signing for the Knicks.
"Very close, I won't say more than that, I know a little bit more than most, but definitely very close," he said. "I was truly excited when I got traded [to the Cavaliers], but we were, it was, it was close [to the Knicks]."
He also disputed comments from Jazz CEO Danny Ainge, who claimed earlier in the week that Utah's players last season "didn't really believe in each other".
"I don't think we didn't believe [in each other]," Mitchell riposted. "I said at the end of the season, 'don't trade [Gobert]. Let's figure this out, let's do.' And that didn't happen.
"For [Ainge] to say that after six months around the team, I disagree. But you know, at the end of the day, that's his decision."
The 25-year-old spent five seasons in Utah, averaging 23.9 points per game, as well as 4.2 rebounds and 4.5 assists.
