I think the idea was that the gas would be so much cheaper that it would have offset the mileage difference. Of course, that never happened. I'm waiting for switchgrass gas.
Ethanol was also harder on older cars when it first came out because of the gasket material they used to use. Currect gaskets in autos usually aren't really rubber so there is no wear penalty in your car anymore. I'm surprised that the small engine industry never followed suit.
I know a few people who have never even unboxed their generators and don't have any gas to run them, but feel prepared.