This is a picture of a ship that has been on the Oregon coast for about 100 years.
Seeing the kind of damage that rust can do, I've resolved never to leave my bike exposed to daily soakings of salt water for 100 years. At least not without applying some kind of frame saver.
I leave my bikes out in the rain when I'm at work. I hang them up wet in the garage. I didn't use frame saver. Once every week or two I brush off the excess grime. When the chain starts to make noise I clean the drivetrain and lube the chain.