Another point in all this is that the ATCO is thoroughly conversant with his or her local area and will be aware of every hill and every obstruction, including temporary ones.
The (non-based) pilot will be relying on documentation which may or may not be accurate and up-to-date, may or may not be easily legible (particularly in bad weather or at night) and he or she may or may not mis-read the documentation due to tiredness, under-preparedness or unfamiliarity with the format.
Given that imbalance does it not behove the controller to provide a service which at the very least is possible with repect to obstacles and ideally is completely safe?