Harkham Hillel Hebrew Academy is the only Orthodox elementary school in Los Angeles who admits troubled kids. Other yeshivos don’t want the aggravation.
So let’s say you let in a hyper-active kid who creates a lot of tsures (trouble). What about the impact this has on other kids? On disrupting the learning environment?
These are tough choices a school must make. I don’t envy the leaders.
Yavneh gets to maintain very high standards because it knows that kids who don’t get in can go to Hillel. If there weren’t a Hillel around, Yavneh would have to relax its standards.