Walker wrote that 2/3rds of adults get less than the recommended 8 hours. But 8 hours aren’t recommended, 7-9 are. And that means far less than 2/3rds of people are failing to meet that. That’s a huge deal for a fundamental claim.
That's assuming the distribution within that range is uniform. The edge case would be that 1% of population being recommended 7 hours and 99% recommended 9 hours. But the recommendations of that nature are typically imprecise anyways.