Why do the war poems in The Book of Songs express the poet's homesickness?

This kind of poetry reflects people's nostalgia and yearning for a peaceful life. Only when they have experienced war can they appreciate the beauty of peaceful life and express their boredom with military life and nostalgia for peaceful family life, but they do not directly express their opposition to war and reprimand those who call for their service. The mood in the poem is mainly sadness, and there is almost no anger. This is because, from a collective point of view, joining the army is an obligation that individuals must fulfill, even if it hinders the personal happiness of soldiers, there is nothing they can do. Such as Feng Weibo Xi and Dongshan.