Let me start with the fact that I'm prepared for this question to be closed as opinion based, but I am going to attempt to phrase it in such a way to keep it less based on opinions.
The Short Version
Are there any practical or best practice resons why configuration settings should not be stored in a Resource (resx) file?
The Long Version
Until recently we were storing application settings in an app.config file and everything was fine as far as I was concerned. A descision was then made to move these settings to a resource(resx) file. The argument being that it provided easier acces to the settings in code as you don't have to remember the key in the resource file (could be overcome with Custom configuration Sections). We also had other settings in the resource file so the additional argument is that we now only have to manage settings in one place. To me this doesn't quite seem right. We have other, in house, components that have been able to be configured via a standard .config file, but this has now changed to fit the new pattern.
Are there any practical or best practice resons why configuration settings should not be stored in a Resource (resx) file?