re: the downward spiral trend, I had a convo about this with an MSTP director at one school. He wanted my honest opinions on the issue, and I told him that not everyone wants to be a pioneer. Med school is hard enough without also having to be the token minority (which is what you can easily become when no one else looks like you; there's a reason why my college always wanted me to pose for the recruitment brochure. haha). My final decision was made more difficult by the fact that some of the schools I liked the most also made the biggest deal out of my race; their emphasis made me uncomfortable, yet they felt the need to reassure me because they only had a handful of students who were URMs. I ultimately decided to disregard that issue since I've survived just fine in predominantly white elementary, middle, high, and secondary schools... but for many students of color, it's a real turn-off to be that isolated from the familiar or relatable. Because the unfortunate reality for minority students is that you are often forced to be the poster child for your race, to educate your peers during diversity discussions, to recruit prospective students of color, and to be above reproach as many will see you as a representative of your demographic. Not everyone wants to accept that responsiblity.
