True enough, maize isn't currently a very good crop fro making ethanol, because existing manufacturingt methods aren't good enough to convert more than a fraction of the plant. That means at present it's not a good plant to be growing for biofuel. That could change, it's just a matter of technology.

But whether you make it from maize ("corn") or sugar beet or sugar cane, it's still ethanol, which si an excellent fuel for cars. And from that story it looks as if Obama was talking about etrhanol, not specifically about maize.

Incidentally one of the best crops from this point of view would, I believe, be hemp. As grown by George Washington and Thomas Jefferson.