I am not sure it's so black and white with encryption. It depends on your threat model. Keeping it secure from an angry ex-girlfriend is one thing, but keeping it secure from a three letter agency is another.
The mistake you are referring to is someone that assumes "encrypted" means three letter agency safe, which is a pretty terrible way to leverage encryption. In that case, it's exactly like hopping in a Tesla and assuming auto pilot will take you home without your supervision.
>The mistake you are referring to is someone that assumes "encrypted" means three letter agency safe, which is a pretty terrible way to leverage encryption.
That's not a mistake, that's table stakes. People reading that X offers "encryption", should assume its cryptographically safe to the standards of the day, and be given that.
Not just some "safe from your spouse, ...maybe..." glorified rot13.
Else, just don't offer it. It's not Vim's place to offer "file encryption" anyway, especially if they can't keep that promise. It's fine not to offer it.
And it doesn't have to be a "three letter agency" that's the threat. The "angry ex-girlfriend" could might as well be a programmer. Or have a script-kiddie nephew. Or know a person or two who can use off-the-shelf tools to decrypt it. And the file might have things like a person's bank account passwords.
The mistake you are referring to is someone that assumes "encrypted" means three letter agency safe, which is a pretty terrible way to leverage encryption. In that case, it's exactly like hopping in a Tesla and assuming auto pilot will take you home without your supervision.