Its an accurate term, though, for those who take an obsessive approach to the general of their choice, and who feels the need to defend their chosen one excessively. Its an apt description for many on here, especially when they acknowledge they cant appreciate another general because it would somehow diminish their love of their general of choice, instead of taking a more balanced view.
Basically, when you call others "Grantists", you are calling them fanboys of Grant, as if they have an excessive opinion of Grant.