The undergrad school name adds a positive weightage for international applicants. There is little means of knowing the quality of the program, grade comparison and abt grade inflation. Having aluminus or attending students from the same univ is a plus and overall reputation does matter.
I also agree that it is not as important as the other parts of the applications like sop, lor, publications and research exp, work exp. Emphasis on gre and gpa depends on the program and adcomms of the respective univ. It is used mostly used for financial aid consideration and rarely for elimination if u pass the min requirement.