What he _actually_ said is slightly more nuanced:

   If you were to ask me to choose between Steam Controller and a 360 
   controller, I would choose 360. Don’t take that as slight to the controller 
   though because it’s more about the comfort of familiarity over 
   functionality. I would choose a 360 controller because I have several 
   thousand hours experience using it, however if tomorrow all game controllers 
   were wiped off the earth and the only option was the Steam Controller, I 
   don’t think this would be a bad thing. In fact, I don’t think gaming would 
   miss a beat.