There has been some discussion in the comments about how some colleges may be admitting "diversity" students at the detriment of otherwise qualified white and/or male students. Here's my personal experience from six semesters of teaching introductory calculus and statistics before returning to full-time student status to finish my PhD. I taught at a relatively selective (<10% admissions rate) school that ranks in the top 100 nationwide and is highly ranked for most of our technical majors (we offer humanities majors as well but they are not highly ranked). I had over 400 students during this time.

Nearly all incoming college students are poorly prepared for college level math (and probably other subjects, but this is where I have experience). Gender doesn't matter. Race doesn't matter. The only consistent signal that I've found is that students that took AP calculus were even less prepared for college level math than those who had not- this was noticed by nearly all our faculty and led to our decision to not accept AP test scores for credit. Obviously there were good students who had AP classes, but the majority thought that they knew a subject because they had memorized a few differentiation and integration shortcuts. They messed up on the fundamental arithmetic so much that they often couldn't apply the shortcuts correctly. The AP student's belief that they were "better" than the other students seemingly led to a worse work/study ethic. Their idea that they could memorize a few common question types and be ready for a test really hurt them when we asked questions that even remotely tested their understanding- we often worked out how to optimize a fence enclosure where one side was a pre-built wall, but the final exam included a problem where two sides were pre-built, and most AP students failed this easier version of the question.

I guess what I'm saying is that most of the existing tests aren't useful when it comes to predicting college performance- there's a significant correlation, but the variance is so high that we might as well not even use the information. To add on to that, most of the "advanced" courses don't do a better job at preparing students, and neither do "college prep" courses. All they do is train students how to answer standardized tests. So people complaining that white kids with high test scores are being left out of college in favor of black kids with lower test scores are making a faulty argument. Those test scores don't indicate that those white kids would be any better students, and the hovering parents that insisted that their kids take all the advanced classes are probably doing their kid a disservice.

So what do colleges actually want? They want students that will graduate and increase the prestige of the college, which leads to a cycle of better admissions and even further prestige. Graduates can do this either by donating money (which is why we let in rich kids as legacy admissions), or by doing something noteworthy (such as being the first black-Jewish-woman astronaut). A middle class white kid just doesn't appeal to a college in any special way, because they probably won't become insanely rich, and their accomplishments won't be that great. As a final secret for anyone still reading, female Native American applicants get the most "bonus points" for diversity. While gender gets some basic scrutiny, ethnic heritage is very rarely verified so now you have an unethical way to help your white kid get into school.