Mark Cuban says Bluesky has “grown ruder and more hateful” and warned that a “lack of diversity of thought” on the platform is pushing users back to Elon Musk’s X, the social network formerly known as Twitter.
The billionaire entrepreneur and longtime tech enthusiast had been one of Bluesky’s most visible champions, but now says the platform’s predominantly left-leaning user base has created a hostile echo chamber where dissenting or even mildly nuanced opinions are met with outrage.
“The lack of diversity of thought here is really hurting usage,” Cuban wrote this week in a series of critical posts.
“There used to be great give and take discussions on politics and news. Not so much any more. Doesn’t have to be this way.”
Cuban, the tech billionaire who once owned the NBA’s Dallas Mavericks and who recently concluded a lengthy stint as one of the investor “sharks” on the hit reality show “Shark Tank,” posted a link to a Washington Post opinion piece titled: “The Bluesky bubble hurts liberals and their causes.
In the piece, columnist Megan McArdle argued that the platform’s left-leaning user base fosters a political silo. Cuban agreed with the piece’s assessment.
“The moderation and block tools on here are so advanced, if you see someone you don’t want to see on here, just block them. Don’t attack them,” he added.
He supported Kamala Harris during the 2024 presidential election but didn’t donate to her campaign, joined Bluesky in late 2024 and has posted nearly 2,000 times since.
His first post — “Hello Less Hateful World” — set a hopeful tone. But that optimism has since faded.
“Engagement went from great convos on many topics, to agree with me or you are a nazi fascist,” Cuban wrote. “We are forcing posts to X.”
He said even small disagreements are met with outsized hostility.
“Even if you agree with 95% of what a person is saying on a topic, if there is one point that you might call out as being more of a grey area, they will call you a fascist etc.,” Cuban wrote.
According to Bloomberg Billionaires Index, Cuban’s net worth stands at approximately $8.35 billion.
Some users didn’t take kindly to Cuban’s critiques — and they made their feelings known in blunt, often profane language.
In response to his concerns, one user wrote, “Go wipe your crocodile tears with a wad of hundreds you tw-t. People are over the idea of ‘cool’ billionaires.”
Another told him, “Man if I were as rich as you I’d probably be less of a p—y,” while a third simply said, “F–kin leave then, p—y.”
Yet another post, which Cuban also reposted, read: “It’s like you, as a billionaire, are a despicable bastard and we want you to stop pushing AI and big business here and just Go Away.”
Bluesky launched as a decentralized social media alternative and saw explosive growth in the aftermath of Elon Musk’s full-throated endorsement of Donald Trump’s reelection campaign in late 2024.
Musk’s backing of Trump triggered an exodus from X, driving millions of liberal-leaning users to Bluesky in search of a quieter, more ideologically aligned environment.
Between November 2024 and May 2025, Bluesky’s user base tripled — from roughly 10 million to over 30 million — according to Pew Research Center. That analysis also found that many of the platform’s most prominent news influencers lean left politically.
Bluesky CEO Jay Graber acknowledged the politically driven migration in a June 4 podcast interview with Vox’s Peter Kafka.
“It’s people wanting to just try something new. It’s people finding their community here,” she said.
“I think in general it’s both people looking for something and people looking to get away from something.”
But for Cuban, that community appears to have turned inward. He now worries the platform is discouraging debate and becoming a digital echo chamber.
The Post has sought comment from Bluesky.
