Correct, however this is a added property, as it is an inerrant property of ethanol, to both separate from petroleum based gasoline, as well as draw moisture from the air. Pure gasoline can sit significantly longer with little or no effect.
E-10 Alive: The corrosive damage ethanol gasoline does to your fuel pump
That's like saying milk is unsafe because somebody left it in the fridge for 2 months and got sick.
I've been looking into this for some time and it seems if used properly there are no problems but lots of benefits like cleaner burning and higher octane for detonation protection.