The most likely case is that the EFI system does not have enough control authority to trim the mixtures for fuels that have very different stoichiometric ratios. For example, E85 may require up to 30% more fuel volume than gasoline. That means you need fuel injector with 30% additional capacity _and_ EFI logic to drive them. It's not very hard to do, it just hurts the bottom line.

The information in that article skirts the border of misleading and bogus. Almost any modern (EFI) gasoline engine is capable of running an alcohol fuel with minimal modifications. Many engines, such as low displacement supercharged ones used in small cars, _will_ run more efficiently because of the higher octane rating. Ethanol is a very effective cleaning product. Many people seems to believe it can "gum" up engine parts while in reality it is simply stripping precipatates off the fueling system itself that may have built up over years of use.

My life isn't over, you insensitive clod.

Infected, you insensitive clod!