In The Atlantic, Christine Folch wonders why fantasy and science fiction are so popular in the West. Her explanation is applicable to steampunk as well.
Folch cites nineteenth century German sociologist Max Weber who argued that economic and political progress had “disenchanted” Western societies.
Weber posited that because of modern science, a rise in secularism, an impersonal market economy and government administered through bureaucracies rather than bonds of loyalty, Western societies perceived the world as knowably rational and systematic, leading to a widespread loss of a sense of wonder and magic. Because reality is composed of processes that can be identified with a powerful-enough microscope or calculated with a fast-enough computer, so Weber’s notion of disenchantment goes, there is no place for mystery.
But people like mystery. “And so we turn to science fiction and fantasy in an attempt to reenchant the world.”
Similarly, steampunk harkens back to an era when adventure and wonder were, in our twenty-first century reimagination of it anyway, commonplace.