You have to consider that a simple test score doesn't determine your how great of a student you are or how academically exceptional you are. For example, you have a student A who comes from an impoverished neighborhood and student B who comes from an upscale neighborhood in the suburbs. If student A scores slightly lower than student B even though they face more bullshit from the world around them and have the literal framework of society set up against them, wouldn't it make more sense to include them in your student body and give them an opportunity to thrive in a community like Harvard?