The image sears through and scars despite the dream-like atmosphere created by the green gas and the floundering soldier. He's too slow to don his gas mask and helmet, which would have saved his life by filtering out the toxins. In fact, it is working too well causing the conflict.
All went lame; all blind; Drunk with fatigue; deaf even to the hoots Of gas-shells dropping softly behind. Owen even uses alliteration to enhance his own hatred of such a violent conflict.
The poem was published posthumously in a book simply called Poems. The dying man is an offense to innocence and purity — his face like a "devil's sick of sin".
But any simple notion of 'passivity' that he reductively levels at Owen is countered in the poem not by the 'tragic joy' that Yeats privileged but by an altogether new kind of aesthetic and empathy.