I got this question from a colleague and thought it appropriate to post my reply herein...
Does anyone know why the "Save to New File..." sometime greys out? It has stumped us.
Because this is how Revit is designed… :-(
RCP, Plan, 3D, Section, Elevation views are project specific and based on internal levels or housed in other system/project specific views.
Some, but not all views can be saved as (or transferred to) external project files; the ones not specific to built in system view families can be, as they are either 2D or parametric/informational.
Views with the "Save to New File…" functionality from a Right-Click:
Here are a few links illustrating the functionality and procedures (an unknowing thanks to the posters of these!!!)...