yes bitcoins will never see mainstream adoption as long as people can literally delete a file or forget a password and lose all their money, no matter what you geeks think. I agree that more services like mybitcoin will emerge, and I suspect the next iterations o cryptocurrencies (the ones that do catch on after BTC crashes and burns) will have much different ways of dealing with this.

It simply isn't reasonable to ask people to take the risk that their money can disappear because of an unbacked-up file.