You may be misunderstanding the meaning of the poem, which is contrasting the grieving/mourning/funeral traditions of a civilian death in Edwardian Britain with necessary differences in ceremony when soldiers are killed in action.

Indeed, there were large numbers of missing for whom no funeral or burial could be held at all.

That’s not to say there was a practised indifference to casualties and fatalities. Indeed, the BEF’s medical services on the western front were a great advance on previous wars (particularly the forward casualty clearing stations). This type of thing was not implemented in the Dardenelles or Mesopotamia with horrific consequences. (See Gary Sheffield – The Chief: Douglas Haig and the British Army)

It’s of note that in comparison to the Boer war a decade previously where 13,000 died of disease compared to 8,000 to enemy action, fatalities due to disease were by now a small minority, rather than a majority which speaks for the considerable advances in casualty care.

Morever, the dead were not simply thrown into mass graves but were buried in marked graves with wooden crossing giving what details could be had (Name, rank, date of death etc.) and extensive efforts were made after the war to find, identify and bury the missing. The graveyards are now carefully manicured plots with permanent stone markers.

Then there’s the large number of memorials built, ranging from the memorials to the missing at Theipval and Ypres, to the Machine Gun Corps and Royal Artillery memorials close to Hyde Park, through to The Cenotaph and of course the almost ubiquitous war memorials in virtually every town, city, village, and major railway station in the country.

None of this support the position that there was any form of apathy to the war dead.