Schools don't reject applicants for being "too good", they reject them for not being a good fit. If you have a 40, 4.0, and are clearly interested in biochemical research, have no interest in public or global health, no ties to an underserved community, and you apply to a school who has average lower stats and a mission statement to help get medicine to underserved and international communities, you are going to get rejected. If it is clear that your intentions and interests don't match with that school's, then it isn't going to happen, they know you're using them as a backup and wouldn't really go there not just because of your stats but because of who you are. If you applied to GW with perfect stats but were able to convince them through your past activities, essays, and LORs that your main interests lie in public health and global research and you want to work with the world health organization in DC and believe that GW would best suit your needs to do so, they won't reject you just because your numbers are high. That's what people say to make themselves feel better about getting rejected from these schools even though they clearly weren't tailored for them. You really have to know how to play the game and pick schools that are appropriate for you as a person to be applying to, not you as a set of numbers.