Wealth inequality in the US is already at absurd levels. The top 1% of Americans have a combined net worth of $34.2 trillion (or 30.4% of all household wealth in the U.S.), while the bottom 50% of the population holds just $2.1 trillion combined (or 1.9% of all wealth).
The Fed estimates that the wealthiest 10% of Americans hold more than 88% of all available equity in corporations and mutual fund shares (with just the top 1% controlling more than twice as much equity as the bottom 50% of all Americans combined).
Well, every time it happened some people had their jobs made obsolete and were fired, and they had to find something else to do.
And every time it happened the income inequality grew because the savings were mostly going as profits for the top levels of company.
Yes, it hasn't been a disaster, but it clearly set some bad trends going.
Or they're mistaken in their assessment of what's going to actually happen, as they frequently have been when it comes to technological progress.