B+
I dont really like him but there is no question that he left his print in the Hollywood Cinema.
Though he is no John Carpenter.
Without strife, your victory has no meaning.
Without strife, you do not advance.
Without strife, there is only stagnation.

I gave him a B+.
He wasn't a top tier film-maker, and most of the films he made were B grade stuff, but he knew how to deliver, was great with atmosphere and he always got decent performances out of his cast.
His mainstay genre being horror and he made original efforts that really emboldened the genre. He is an iconic director in this respect and he made a lot of money for himself and Hollywood, and they knew they could rely on his name for marquee value.
Norman! What did you put in my tea?