... article mentioned that if we took all the biomass from all of the farmland both producing and fallow and were able to convert it all directly to ethanol that it would STILL only account for 14% of the US energy budget.
(Ignoring for the moment whether the claim is accurate ...)
The idea is not to replace the whole energy needs of the country with biomass fuels. Smelting steel or refining aluminum with it, for instance, would be downright silly. Ditto running power plants: (Even if you wanted to use biomass there'd be no reason to waste part of its energy liquifying it - just burn it directly. But there are lots of cheaper alternatives.)
But there's a small-but-substantial fraction of the load for which liquid fuels is ideal: Vehicles. Liquid fuels provide enormous power-to-weight ratios, which is what you want there. Keeping a vehicle light pays dividends in fuel savings, as does providing energy using easy-to-handle liquid with high energy content.
The base process ferments cellulose into butanol, acetone, and ethanol. Even without this new post-processing hack, butanol is a drop-in replacement for gasoline, ethanol works in otto-cycle engines with a little tweaking and acetone with more tweaking. This new post-process turns the mix into something akin to fuel oil, which is a similar drop-in for diesel cycle engines. So it covers both major types of portable engines.
Even if you can't come up with enough fuel to run the whole economy, or even the whole transportation industry, from locally-grown biomass, there's a LOT of low-value byproducts grown in the process of growing crops. Turning it into high-value portable liquid fuel could make a substantial dent in oil requirements while improving the financial picture both for vehicle users and farmers.
Solar and wind aren't well suited for the enormous energy and energy-density needs of land vehicles (though we're getting closer with modern electric vehicles for limited ranges). But they can make a similar dent in the energy needs of stationary loads.