This is an excellent and profoundly disturbing poem where the strong, handsome youth before he goes to war is ironically compared with the shattered, wheelchair-bound remnant of humanity that returns after having his life destroyed in war. Although the point of view of this poem is third person omniscient, let us also note that particularly towards the end, the speaker of the poem presents us with the thoughts and voice of the young man himself, especially in the incredibly poignant ending of the poem:
How cold and late it is! Why don't they come
And put him to bed? Why don't they come?
This of course clearly points towards both the fate of the injured soldiers who live out the rest of their lives as being disabled, and also the way in which they are so destroyed by their experiences that they wish to be hidden from the gaze of the "normal" people who are able to live their lives free from the stigma of being wounded and disabled.
If the poem were written from the soldier's perspective, I think it would have made the poem far more emotional in terms of how it would have conveyed the soldier's longing and loss. Instead of having the speaker of the poem tell us how much the man wants to feel the slimness of girls' waists, we would have the soldier's own words to explain his desire and unrequited longing, which would no doubt have added greater impact to the poem. However, I think one of the reasons that Owen wrote this in the third person was to reinforce the way that this poem is an object lesson. If we rush off to war like this young man did, we risk a very uncertain future. The point of view helps us to look in on this man as an object lesson which reinforces the central message of this poem.