Recombination is a trait that increases diversity of a population, but its also a trait that increases the fitness of the individual organism's lineage as it allows greater diversity of genetic material and interactions between genes in its offspring. So there is an organism level effect that promotes the selection of recombination.

I originally granted that there are traits that can be seen to promote population diversity, but that they would be selected for by the increased fitness at the organism level, not because populations with more diversity better survive random black swan events.