There is plenty of poetry about and influenced by WWII but I think there's lots of reasons why WWI has become, in the UK public's mind, the poets' war. First, there was the deliberate effort by the WWI poets (most of them) to deal with the conditions, scale, scope and pointlessness of much of the war - both for themselves but also to cry out on a public basis. (Similarly, in terms of highlighting the cause, see the Spanish Civil War) There's a view that WWII, as a just cause, did not require such conciousness raising (it was also a civilian war in the UK in the way WWI was not). Also, if you were a poet in WWII, how did you respond in an artistic sense to what were already known as the War Poets, and to the Spanish war poets? Then there's the effect of the mass media. Although there was a rabidly patriotic print press in the UK, WW1 was fought without mass radio, film, TV and the internet to tell the story. This means the written word is much more dominant in the artistic response to the war, and also meant an alternative commentary to the official story was lacking. Finally there's perhaps something in the scale of its impact on British consciousness - twice as many deaths as the Second World War and the first time the country had experience such scale of loss - that impacted on the artistic response. Quite simply there was a need to understand what had happened through an alternative telling of the war. It was the poets that provided this narrative of brave lads undermined by idiotic commanders, and that is the story of the war that has become the truth for most of the public, which in turn has reinforced the poetry as the primary artistic response to the war.