Tabasco,
Did you listen to the program? The commentator makes the same points you do. The grain and switch grass ideas were criticized because of it. The waste gasification, however, shows great promise because it's material we need to produce anyway. The waste biofuel is produced from food waste and other organic waste that we would need to produce (such as food, scrap lumber, paper, packaging... etc.) Plus, it is much more productive, since the energy that is needed to produce it can be created from the inputs themselves (after a bit of a startup "spark")
In any event, the program gives an interesting overview of where we are on the development of these technologies. As Maurice points out, in the history of everything that does work is a long period of time where it didn't.