Ethanol in small engines

Roadpilot wrote:

Water is heavier than gas so is at the bottom of the tank. Generator pickups are often raised up to the quarter full level so you can't run the main tank dry using the generator.

What does that have to do with ethanol in gas sitting in the tank and supposedly causing problems? I've left my rig sit for 2-3 months straight on multiple occasions with 1/2 a tank full (this year 5 months...too busy to camp unfortunately). Generator wasn't run for 3 of those months. Genny fired right up and ran 3 hours with a load no problems. Rig fired right up too with no problems.