You're right, I remember it now. I used the wrong terminology in that case. Honestly, the end result is the same. I'm sure there were reasons to use multiple workspaces for different pieces of code and the same user of the same program would still want it to look and feel the same rather than getting thrown the defaults back in your face when starting a new workspace...
But that's exactly the problem! The minute you want to change a key binding or a hotkey, you have a re-export that change to all your workspaces.
Honestly it reminds me of GIMP taking years to finally implement an MDI interface. If only eclipse let me keep the same bindings, UI, etc across different workspaces I probably wouldn't have switched.
I use different workspaces for different projects because of differences between code formatting. One project uses 3 spaces and the other uses four spaces. One has curly braces on the same line and the other on their own line.