I agree with the author. Part of it is the two foot, ten foot interface thing.
I think time is another thing. Everyone has different needs, but everyone only has so many hours in a day. I know that I spend more hours a day on satellite and broadcast radio, streaming audio, podcasts, YouTube, and Netflix, than I do on TV. I certainly do not want to dedicate a computer to such a limited pupose.
And have you ever tried to run a computer, only using a remote control? Need I say more.