It's there in case the `rcParams['savefig.directory']` key was missing. Maybe the user deleted it from the `rcParams` dict after initialization by `rcsetup.py`? Perhaps that's unreasonable to worry about. I have the same `if` block in the other backends. I could remove it from all backends, and then to be consistent, change all instances of `rcParams.get('savefig.directory', '')` to just `rcParams['savefig.directory']`.