Any written work you submit the an English professor/teacher, must pass the sentence structure/grammar/spelling test, before facts, consistency, and logic even enter the equasion.
It doesn't matter if they are teaching a course in creative writing, business report writing or kids birthday party name-tag writing, the English basics come first.
They can't help it, it's the nature of the beast. We've even seen it here on this board.
But yeah, it's W's fault.