The sorrow and the pithy: Why short stories are rarely "life affirming"

A friend asks if there are any short stories that are entirely life-affirmative (part of the FR Leavis criteria for "great" novels), and that's a really tough question to answer. First let's take off the table stories that are overtly comic (e.g., The Kugelmass Epiode) or formally playful and inventive (stories of Calvino, Barth, Borges, for ex.) but stay with stories in the realist-naturalist tradition. And the quick answer is - no - pure life-affirmation finds little or no place in the modern and contemporary short story. Some stories, sure, may have so-called happy endings, but always or almost always with some nuance or shadow of sorry. In American short stories in particular the characters tend to be loners and isolates, often life's losers, and though they may survive through the story we don't feel that their lives are complete and whole and promising. I'd be interested to hear about exceptions to this broad generalization, and some stories may give the reading a feeling of uplift, although the journey to that point may be poignant and even heart-wrenching. At the top of that list I'd put some of the stories by IB Singer, notably Gimpel the Fool and Crown of Feathers (title stories to 2 of his collections). I might add in some stories by Lorrie Moore - for their wit - even though the protagonists are often lonesome young women for whom we can't help but feel some sorrow. Ann Beattie's stories are also witty and sometimes upbeat: I have described her characters as unlucky in love but lucky in friendship, and that sometimes is enough to make her stories life-affirming. Old friend Charles Baxter would be similar - very finely written stories about people trying to get along in life and sometimes they do. But overall stories seem, with the tight and strict demands of the form, seem overwhelming to involve struggle, crisis, loneliness, social isolation - and they rarely if ever seem to end in a crisis resolved and a feeling of harmony. The classic conclusion of a romantic comedy or a bildungsroman needs more space and scope to develop a network of social interaction and romantic inclusion.