I am not a sociologist.
Normally, this doesn’t really mean anything. I’m not a lot of things. I’m not a firefighter, or an accountant, or a Buddhist, or an anarchist, or a zucchini. Normally, these are all of about equal relevance.
In this case, however, the fact that I’m not a sociologist matters a little, since what I’m suggesting dips a toe into those waters. But I’m going to speculate anyway, and if I’m way off base, well, it wouldn’t be the first time.
(It would, in fact, be the seventh. I have been wrong exactly seven times in my life. Or eight, if you count this assertion.)
Anyway, all of this is just me dithering aimlessly, so enough of that. It’s time to dither with purpose.
Trends and tastes in entertainment tend to rise and fall in cycles. Something’s popular for a while, falls out of popularity, the pendulum swings back and it comes back for a while, and so forth. Some details my change. Maybe sword-and-sorcery fantasy is popular during one surge, whereas sweeping epics are dominant in the next (Not that such things can’t both coexist, of course; I’m just talking trends being more or less common.) The details may change, but the core aspect of a genre/style/whatever—and the purpose it serves for its particular audience—returns.
My hypothesis, after giving it some thought, is this: The surge in popularity of steampunk over the last decade or so is an upswing in the same cycle that gave us the popularity of epic fantasy from the 70s to the 90s. Not similar. Not related. They are the same cycle and fill the same needs for the speculative fiction audience; only the cosmetic details have changed.
Yes, you now think I’m crazy. Steampunk and high fantasy are pretty far apart on the spec-fic continuum, and when most people do look for connections, they suggest a much closer link between steampunk and sci-fi than between it and fantasy (due, in part, to the reliance on technology).
And you’d be right, I am crazy. But not because of this.