Mark Cuban is sounding the alarm on Bluesky’s declining engagement — and he’s not pulling his punches.
In a series of Bluesky posts, the billionaire investor and entrepreneur criticized the platform for fostering an echo chamber that he said was driving users away and inadvertently boosting traffic back to Elon Musk’s X.
“The lack of diversity of thought here is really hurting usage,” Cuban wrote, linking to a Washington Post opinion piece headlined “BlueSky’s decline stems from never hearing from the other side.”
Once known for “great give-and-take discussions on politics and news,” Cuban said Bluesky had become a monoculture where dissent was unwelcome and nuance was vanishing.
“Engagement went from great convos on many topics, to ‘agree with me or you are a Nazi fascist,'” he posted.
A graph of Bluesky’s unique daily posters supports his concern.
On February 28, Bluesky had more than 1 million unique users daily. Since then, engagement has plummeted, with June 7 and 8 hovering well below that peak at about 670,000 daily posters.
The Musk factor
BlueSky’s rise accelerated following the election of President Donald Trump, whom CEO Musk backed financially, and after X introduced new terms of service.
Many X users migrated to Bluesky, with some 2.5 million joining in one week in November.
Some were seeking a friendlier, more open platform with less hate speech and misinformation, and more control over what content is shown in their feeds.
A startup, BlueArk, even sprang up to help users migrate their X/Twitter histories to Bluesky, porting over millions of posts and creating the illusion of continuity on a new platform.
At the time, Cuban told Business Insider he preferred Bluesky over alternatives due to its variety of content and growing engagement.
Now, some of the earliest and most visible converts, including Cuban, are questioning whether the migration created a new community, or just repackaged the same silos.
“Why would anyone stop using Twitter if the only topic that is acceptable to you is news and politics?” he asked.
Cuban also criticized the platform’s culture, saying: “The replies on here may not be as racist as Twitter, but they damn sure are hateful.”
Posts about AI, business, or healthcare — traditionally strong areas for Cuban — often gain little traction or were met with outright hostility, he added.
Cuban also questioned Bluesky’s business model: “How does everyone suggest BlueSky survive as a business? Or do you not care?”
