It's not so much that the universe is hostile, more that humanity is a total irrelevance, even to itself. Gibson also gives you worlds which have gone to hell, but the protagonists do manage to establish meaningful relationships in one way or another, in the face of disaster. Watts denies us even this. It's Lovecraft for grown-ups. Humanity is a meaningless accident in an ancient uncaring universe and we will bring about our own downfall without the need for ludicrously--named horrors.
To shift milieus, Gibson to Watts is like The Day of the Triffids vs The Death of Grass. Both are journeys to safety through an apocalyptic England, both reach their goal, but one gives you a glimpse of hope, the other snatches the hope away and says that no, there is nothing left.