"It's a joke. It's stupid and it's silly," Barkley said during the "Inside the NBA" telecast Tuesday night.
The 76ers announced late in Tuesday's practice that Simmons has been suspended one game for conduct detrimental to the team, a suspension he'll serve for the opening game Wednesday against the Pelicans in New Orleans.
Simmons had been thrown out of practice by Rivers after he declined twice to sub in for a drill.
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"I just thought he was a distraction today,'' Rivers said Tuesday after practice. "I didn't think he wanted to do what everybody else was doing. It was early. It wasn't a big deal. I just told him he should leave. We went on with practice.''
Barkley said this ordeal is "everybody's fault."
"Ben Simmons deserves, number one, the blame," Barkley said. "Because when people ask you to be a better basketball player and they're paying you $35 million, $40 million, that's a very fair thing.
"The Sixers deserve some blame because they already let this guy not improve and get one coach fired. They threw (former head coach) Brett Brown under the bus.
"And the third thing is (head coach) Doc Rivers. Last year, (he said) 'you guys want me to take Ben Simmons out the game?' Yeah, we do. If he's just going to stand there and not shoot the basketball - yes, we do.
"So there's plenty of blame to go around. But the number one blame goes with Ben Simmons.
"Your coach. Your mom and dad. You should want to be a better basketball player because that's your profession, that's your job. Your coach is important. Your mom and dad's important. But I wanted to be a great basketball player for myself, first and foremost."
Former NBA Champion and fellow cohost Kenny Smith said Simmons "moved the pendulum" by showing up to practice disgruntled and "now, it's your fault right now."
The 25-year-old Australian guard still has four years and $147 million left on his max contract.
"Inside the NBA" cohost and NBA legend Shaquille O'Neal said Simmons' goal is to force a trade.
Shaq proposed a question to the rest of the panel, "Who's going to want to pay a guy $150 million who's not going to shoot the ball in the fourth quarter?"
Barkley responded, "Nobody."
"Living in Philly all summer, I have been asked that every single day, multiple times...I said, 'you guys are acting like there's (a team) saying give me a guy making $150-million for the next five years who can't shoot the basketball or can't make free throws. It's not that simple," Barkley said.
The 76ers have fined Simmons $1.4 million for his absence from four preseason games ($360,000 each) and levied numerous team fines for missed practices, on-court workouts and meetings, sources told Wojnarowski. Simmons hasn't earned any money since returning to the team on Oct. 11.
By being suspended for Wednesday's game, Simmons will lose roughly another $227,000.
Barkley said the Sixers will be better once Simmons is traded.
"You can't have a guy acting like that on your team," Barkley said.
In the wake of suspension, current teammate and superstar center Joel Embiid said he has yet to speak to Simmons, and declared -- several times -- that it isn't his job to "babysit" anyone.
"I'm trying to win," Embiid said. "And to win, you have to have that relationship with your teammates. I do have that relationship with all my teammates.
"But at the end of the day, our job is not to babysit somebody. We get paid to produce on the court, go out, play hard, win some games ... that's what we get paid for. We don't get paid to come out here and try to babysit somebody. So that's not our job, and I'm sure my teammates feel that way.
"We're really focused on just winning and playing as a team."
Barkley said he's glad Embiid is "finally stepping up."
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"Joel Embiid needs to say 'I'm the best player here. This is my team. I ain't got time for this b-s this dude's got going on,'" Barkley said.
Barkley said even if Simmons comes back and the team makes the playoff, he won't shoot the ball and the Sixers will be in the same situation they were last postseason.
During Game 7 of the Eastern Conference semifinals against the Atlanta Hawks, Simmons passed up an open dunk that would've tied the game with less than four minutes left, and the Sixers went on to lose and see their season come to an end.
A short time later, Simmons asked for a trade, and he then held out the first two weeks of training camp in an attempt to force the 76ers to make a deal. Instead, he reported to the team last week, and after going through several days of re-entry protocols, Simmons practiced with the team Sunday and Monday before being tossed from Tuesday's practice.
Since returning to the team, Simmons has not spoken to the media, and he hasn't said anything publicly since that Game 7 loss. That has left Rivers and his teammates to answer questions about the situation for him.
When asked what he should do with a player that has shown he doesn't want to be part of the team, Rivers said that doesn't change his job description.
"Every day, every single moment, I'm going to give Ben a chance to join the team, and be part of the team," Rivers said. "He's under contract to be part of the team, and that's not going to change. Sometimes it happens quick and guys join back in, and sometimes it doesn't. I've been in both situations, and I'm fine with that.
"My job as a coach is to keep trying to get guys to buy in, to be in, and unfortunately this is tougher, this situation, but that's my job. I'm not going to stop my job."
ESPN contributed to this report