Marxist criticism isn't, as it seems, taking a socialist view of the text; rather, it views the text as political and social commentary, asking questions about how class is reflected, what it says about oppression, and statements it makes about social conflicts.
"Disabled," by Wilfred Owen, was penned during World War I, a war renowned for the stupidity and abuse of power rampant among its leaders. The poem speaks of a young man who lied about his age to enlist: "Smiling they wrote his lie: aged nineteen years" (line 29). This means he was probably 17 or 18, a handsome, athletic young man who was accustomed to being the "hero" of the football field when, "After the matches [he was] carried shoulder-high" (22).
The commentary about the powers that be lies in how he is treated at the VA facility where he lives now, but chronologically begins with the half-truths he is told to entice him to enlist, where the focus is not on the reality of war and the likely outcome of pitting his body against the firepower of the Germans, but on the intangibles and shiny things historically used by governments to entice young men to pledge their lives in hopes of being heroes. He focused on the handful of pleasant, "cool" things associated with service: "jeweled hilts," "daggers," leave, pay, the intangible "esprit de corps" and "hints for young recruits"--the "brotherhood" of the shared experience of service (32-6).
Of course, as a young man, he also did it to "please the giddy jilts" (27)--that is, capricious women, like his Meg, because "he'd look a god in kilts" (25).
Owen suggests that none of these are good reasons for joining the army, particularly since the young man didn't even have a good grasp of what the war was about:
Germans he scarcely thought of, all their guilt,And Austria's, did not move him. (30-1)