Your premise is wrong. You assume that the entrance essay is "graded". It's not. It's meant to give the admissions board more information about your character as a student, and insight into how you express yourself in the day-to-day.

While the essay isn't graded, it is *judged*. It is judged based upon your ability to convey your thoughts and ideas (along with your test scores, 2ndary school grades, extra-curricular activities, etc), and whether that type of expression fits into MIT society.

They can't actually do this in the US.

They can refuse a warranty if the 3rd party part was shown to be the cause of the problem (ECU remapping, for example), but it doesn't go beyond that (they can't refuse the seat mounting rails warranty coverage).