No, I think the thesis is sound. It doesn't really matter whether they were volunteers or conscripts, the vast majority of soldiers were working class, not least because that was the demographic. I'm not sure that agricultural labouring was a lighthouse of good OH&S. What is abundantly clear is that for the middle classes the trenches were an unimaginable experience, and it was from these people that the 'luvvies' of the 1920s were drawn. I do suggest that if you are actually interested in the subject then find the original article.
On another matter, I'm not sure that any British general or staff officer in the 20th century experienced a war that met their expectations. The basic reason for this is that mostly the British did not start them, hence did not have the initial initiative to shape them (which may or may not have been possible for the initiator).
[Apologies for the crap formatting, was trying to keep stuff on Archei'e screen. The quoting thing is a roayl pain in the arse tho. )
Would agree with the last para at least up to a point, but regarding the first part I disagree. The thesis is not sound as you have presented it for a number of reasons, not least because you could argue that the trenches were no less an unimaginable experience for working class men; the latter likely adapted better to military service than middle-class recruits, but military service and the trenches were not the same thing. More importantly, the thesis is too broad brush because it appears to treat the 1914-18 Army as a homogeneous whole whereas it was really three or four separate Armies; the pre-War Regulars, the Territorials, the New Army and the Conscript Army. The social origin of the first is irrelevant and I expect there were a fair few middle-class folk in the Territorials due to its recruiting model. The wild card is the 2.5 million strong New Army which contained a relatively huge number of middle-class men, many of them professionals more than qualified to serve as officers but who preferred to serve in the ranks with their friends and colleagues; in some instances there were entire battalions made up of such men. I also suspect there were more than a few of what we'd now call luvvies, such as writers, poets, actors etc in those rank, and AFAIK the latter occupations were not protected there was likely a proportion of them among the middle-class cohort of conscripts too. I don't think that middle-class familiarity with the trenches was anywhere near as thin on the ground as you suggest, and I don't therefore think the linkage between the middle-class and luvvies is valid either. Now if we take "luvvies" to mean the Bloomsbury Group then yes, their experience of the trenches was virtually nil as the male members of that group were all either conscientious objectors or medically unfit, which I suspect is why their views were virtually ignored at the time. But it is too much of a stretch to apply that to the middle-class as a whole, IMHO.