Allow Export to JSON and Run of Server Workflow

I have been working a lot with exporting client side workflows to a json file and running them directly off of my IIS server using the on premise version of workflow. I had tried the same with server workflows (calling the server workflow from a client workflows). The problem is, it would only work if was logged into ArcGIS Online (from the sandbox). It appears that Server Workflows has a mandatory login to a Portal or ArcGIS Online in order to run. I do not understand why you would allow Client workflows to be exported and run but not server workflows. After all, you are not actually using ArcGIS Online or Portal for anything other than storing the JSON files and the associated meta data.