You wrote “Most striking to me is the paucity-tapering-to-disappearance of love poems from the male perspective. ”
This is I think an accurate description of what actually happened. Basically, the poems from the Book of Songs were actual, well, songs. They were meant to imitate the sort of thing people sung about their way while working in the fields. But as songs become poetry overt love themes are put to the side. I think this is in part because Chinese poets have a different idea of what poetry is supposed to be about. Somewhere in his book, The Mandarin and the Cadre: China’s Political Cultures Lucien Pye makes an offhand observation that in the West sincerity is equated with spontaneous emotional display. From the time of Wordsworth forward, Western poetry is very much about capturing these spontaneous emotions of the moment. But the Chinese tradition tends to distrust the spontaneous, Pye argues. The spontaneous is ephemeral, transient. Your real feelings and motivations are not seen from your instant emotional reactions, but from the long term patterns of your behavior. Love is not about the bliss of the movement but the steady dedication of a life time. Anyone who has been a relationship with an addict can see the wisdom of that approach.
I am spit balling a bit here, but I think some of that attitude finds its way into Chinese poetry. When love is discussed openly it is almost always discussed in terms of a wife missing her husband when he is sent on a journey or called off to war, the poet’s gratitude for her support over the years, whereas Western poets tend to think of love in terms of the love-struck feelings it engenders in the poet or the beauty of the poet’s love.