As much as I hate this term now a days, some way to gameify the idea of using encryption might help spur people's use of the technology. Once enough people have adopted a specific app or software then it's much easier to bring outsiders onboard.
Right now things like PGP are difficult for even "experienced" users to setup and maintain, let alone the average joe. Setting up encrypted volumes, or directories, etc... it just goes over most people's heads and/or their willingness/amount of effort, so they just don't do it.
I think switching from "you should consider encrypting things" to an "everything is encrypted by default" society, propelled forwards by software that makes it easy, automatic, and default... that's when we will make progress.
I think also for that reason it is that our front doors are easy to open by a locksmith without the need of destroying them completely.
Better option than passwords is keys anyway. Way too many services depend on human memorizable numbers, which we know all too well is a transient thing at best - every year, as computational power rises, the "average" password gets weaker, and nobody uses good passwords.
People just need a personal key to encrypt and decrypt with. They need to protect that key, maybe by password, maybe by printing it out. One good key can easily replace all the horrible password schemes in the world.
But software needs to be written, especially save dialogs, to easily "pick" a key to encrypt with, and when you open files a history of keys used and a browser to open keys to decrypt opened files with.
Of course Windows will never have anything like that, but at least Dolphin and Nautilus can look to adopt those kinds of workflows.