Here is what you don't understand 10:17 when you reject a sibling qualified or not you make the families life more difficult. Carpooling, afterschool events, it all becomes very difficult to manage. And resentment grows over time. You can be human and compassionate understand there is a real consequence for families or not care. You obviously do not care. Perhaps that attitude is what truly comes through after all.
I think this post brings up another interesting point. As PPs have pointed out, admissions is building a school community. They are not, and shouldn't be, in the business of making a family's carpooling lives easier. Accusing a school of not having compassion and or being inhuman for not taking your personal schedule into account when accepting students is incorrectly placing the responsibility of your life choices somewhere where it doesn't belong.
Don't resent the school if the commute is too difficult. Make a plan B that better suits your family's needs.