He's basically claiming that if the blocks ever fill up, then Bitcoin has failed.
I have always suspected this guy is a clueless zombie. Quite the opposite, filled up blocks is not a failure but success! Economy is always about supply and demand. Success of a product or service you are offering is measured by how much demand is surpassing supply.
Which is why businesses which are experiencing increased sales do not move to larger premises or take on more employees. Got to keep that supply down...