ZD: Busing for private schools is not a courtesy; it is mandatory by law.
And courtesy busing is provided equally to both public and private schools. And public school students use courtesy busing at a much higher percentage than private school students. (In Lakewood almost half the public school kids use courtesy busing, while less than a quarter of yeshiva kids use courtesy busing.) Cutting courtesy busing will proportionally hurt public school students much more than the loss will hurt private school students. Especially in towns where it is dangerous for little school children to walk to school, due to the heavy local traffic, even if it is “only” a 2 mile walk.
And the typical public school student doesn’t have an available parent to take him to school, and pick him up, every day. The yeshiva students are much more likely to have that.