The James-Stein estimator does not respect translational symmetry. If I do a change of variables x2 = (x - offset), for an arbitrary offset, it gives me a different result! Whereas an estimator that just says I should guess that the mean is x, is unaffected by a change of coordinate system.
This is a big problem if the coordinate system itself is not intended to contain information about the location of the mean.
This makes sense if "zero" is physically meaningful, for example if negative values are not allowed in the problem domain (number of spectators at Wimbledon stadium, etc). Although in that case, my distribution probably shouldn't be Gaussian!