why [was] one of these two high-profile serial killer movies was a star-maker and the other one of the most reviled films produced in Britain

--I wonder this a lot when you have two households works of art, both alike in dignity, and one catches the eye and the other sinks, or worse. Sometimes it's easy in retrospect to see why, and yet apparently it's never easy in prospect. And sometimes (I guess in the case of Tom Thumb) the obscurity or reviling of the one that fails is afterward seen to be unmerited. Go figure.