I'm not from the bottom 50%, but most of my students are.

Many of them come into the 9th grade defeated and numb - from previous failures.

We set the bar high - track them into honors/AP strands and offer a lot of after school hours help. If they can't or won't do the honors/AP strand, then they take the regular (albeit still college track) classes.

This year, three of my previous bottom 50% got full scholarships to Brown, Brandeis and Georgetown Universities.

75% of the others were offered placements and scholarships at other universities (state and private).

So - I'd rather not "throw" them away so early in the game.
I'd rather give them an opportunity to meet high standards, give them all the help they need to do so, and let them then decide where they want to go in life: college, technical schools, military etc.