The tech CEOs have been steeped in the ways of AI prophecy, for the simple fact that it's what sells to the board, to other business sectors, and to the decision makers in governments around the world. Being in a position of power doesn't make them immune to the market forces that have pushed all this hype into the stratosphere. Instead, it makes them beholden to those forces.
And if you push a specific message hard enough for long enough, even if you know it to be 99.9999% complete and utter bullshit, you will start to believe it. The human psyche isn't great about separating fact from fiction if you have to live in that fiction 24/7, and these people don't just live in that fiction, they have to sell it so hard that to risk their own disbelief being found out is far, FAR riskier to them and their companies than the ever so slight risk of adding to the psychosis necessary to be a "successful" business leader to begin with in the tech sector.
And let's face it, if huffing your own farts was an Olympic sport, the tech CEOs would be the champions. Always.