For the same reason little bitty backwater colleges rename themselves "universities," I would guess!
One of the definitions of the word gospel is: "Religious doctrine: The written body of teachings of a religious group that are generally accepted by that group."
Since gnostics accept the "gnostic gospels" as teaching their religious doctrine, I guess that explains the usage. *shrug*
Since gospel means 'good news', it's just an acknowledgement of what they are: the 'gnostic good news'. For instance,
"Good news! You can do whatever you want, you won't go to hell and there is no sin! Why? Because 'we know'...it says so right in our name."
"Good news! The church can't tell you what to do. We have a book right here that says so!"
"Good news! Remember the old pagan goddesses, like Isis and Hera and such? Yeah, it turns out there is no other God than them."
They are all very much like the original gnostic gospel: "Good news! You won't die if you disobey God and eat of the fruit of the tree of knowledge."
All these gnostic works come from the same source, and lead to the same fate.
I think we could safely refer to them as pseudo-gospels...
Commenting by HaloScan
