I've been in exercises where we review applications, resumes etc. When you have thousands of applicants - you ditch the ones with raw scores below a certain amount. Mediocre SAT and B+ level GPA? Dump them. You have a thousand more to finish before lunch time.
They do NOT spend the time scrutinizing every part of your academic record. A perfect GPA and perfect SAT score, they don't care if you participated in anything. Bear in mind, the college, especially an elite one, wants to know if you'll succeed academically. It's just being pragmatic.
What I want to know has nothing to do with COLLEGE ADMISSIONS. What I want to know is, does the HIGH SCHOOL compute the GPA with difficulty as a consideration? As I mentioned - our co-valedictorians took different paths to a perfect GPA, but one took the hardest path imaginable, and the other the easiest. Because my school JUST LOOKED AT GRADES to compute the GPA. I don't know if the easy path valedictorian went anywhere to school afterward - but someone ELSE didn't get valedictorian, because she got in there with easy courses.