E85 lacks basic energy, not to mention the hideous cost of manufacturing.
E85 is less energy dense per unit volume of fuel than gasoline, but for a given amount of air you can liberate more energy with E85 than with gasoline. Also E85 has a much higher octane rating than gasoline so you can run higher boost or higher compression. Higher boost allows you to liberate more energy per combustion cycle while higher compression just increased your Carnot Cycle efficiency making better use of the energy you liberated. Either way producing power with alcohol fuels isn't a problem, only the crappy implementation of consumer flex fuel vehicles that are a crappy compromise so they run sub optimally all of the time (maybe they actually run really good if you can get an E42 mix).
Fuel from field corn sucks, but there are better cheaper ways of producing alcohol fuels, like starting with methane and converting it to methanol or working up to heavier alcohols like ethanol, proponol, or butanol. Butanol should be what is pursued as it can be used as a direct gasoline replacement in existing vehicles with very similar properties and energy densities. It also doesn't absorb as much water as ethanol and better mixes with gasoline.