You probably aren't wrong, but he never said it was.

Here's my idea. It would be like a surly singleator, but with a fork and two pulleys. When you pedal forward, the chain pushes down on the top pulley, which pushes down on the bottom section of chain. When you put back pressure on the pedals, the chain pushes on the bottom pulley, which pushes up on the top section of chain, and everything stays tight with no major forces on the tensioner. In essence, the chain would keep itself tight. One of the pulleys would be adjustable like in my diagram. If somebody makes this and gets rich I want a years supply of beer.