Bugbears, red herrings, bêtes noires, alibis, bogeymen, and shibboleths

I had a professor in a comp lit class as an undergraduate who drilled into us all the zombie rules. You couldn't use "hopefully" as a sentence adverb, but only as an adverb modifying an action: "He waited hopefully." You couldn't begin a sentence with the word "however" in the sense of "nevertheless." You couldn't write "the fact that" because that would be wasted words. You could never use the passive voice. Instead of teaching us other, more valuable things about good writing, he substituted a set of bugbears, red herrings, bêtes noires, and shibboleths. Bogey-men of usage. These are not the "elements of style," but a set of alibis for style, a convenient but misleading set of rules.