If that's right, it's inexcusable. The idea that a proprietary for-profit protocol would be non-portable between two sites that (in principle) support the protocol is a bit hard to imagine.

> If I am using a platform to manage content, I'd like to think that I could easily port that content wherever I want.

That would seem to be an implicit expectation, but maybe I'm being naive.

One of my perhaps unrealistic expectations about proprietary protocols and markups is that they should provide import and export paths to one or more widely accepted generic document formats. Most protocols provide an import path, but, for obvious reasons, fewer provide a way to export.