GnuPG/PGP isn't transport-layer encryption. For e-mail it's a message container that has to be opened separately; similar for files. If you want to store a message plain text, save it as plain text. The problem is that mail clients or their !crypto plugins have tried to make the encryption layer seamless with the transport layer or the message store. The analogy of a (plaintext) postcard inside a (crypto) envelope breaks down — you don't just open the envelope and take out the postcard (so you have only one thing), you have to copy the contents of the envelope into a plaintext format (and then you have two things). That complexity is what makes designing a good crypto UI so difficult.