Why can't friends or family members write recommendation letters for graduate admissions? When browsing their web sites, I noticed that apart from those listed academic requirements by different universities, they all require at least two reference letters from applicants, but they did not officially state that who should write those recommendation letters.Although I have collected several recommendation letters from my former teachers, I found it was quite hard to reach my former teachers whom I had not contacted for many years.It almost took me two months from the day I sent out my first email to the day I got enough recommendation letters from my former teachers.
It has been puzzling me why the recommendation letters should be written by school lecturers or professors.The people who know you best are business partners, your close friends, family members like your parents, siblings, why they are not qualified to write the recommendation letters for me?
Because they cannot be objective.
Because they do not have firsthand knowledge of your academic abilities. 
Because they do not have the background necessary to compare you to other graduate school applicants.


Also see Kisses of Death in the Graduate School Application Process, page 2, "Harmful letters of recommendation," subsection "Inappropriate sources," and Protocol for writing a recommendation letter for someone you only know on a personal basis.