Ethanol carrys moisture which causes corosion on aluminum. It’s widely known and there are a whole aray of products on the market to try to combat it. If you left non ethanol gas in your engine and let it sit for six months odds are strong you would have no problems. If you did the same whith ethanol not a chance. Yes you drain drain and clean and make it work but why bother?
One of the thousands of studies done on the problem http://www.mossmotors.com/SiteGraphics/Pages/ethanol.html