I mean, obviously, the basic aesthetic is delicious.
Part of this is shaped by the infinite ways in which the pollution from the coal fires of industry settled into a patina of detailing: gorgeous grunge, edging the cogs, wheels and rivets. There’s also an appreciation of the useful items–the cogs, wheels, and rivets–outside of the context of their usefulness, as aesthetic objects in themselves. Still another part of it is the tweeds, the silks, and the cottons in richly muted shades, combined with the stylized figures of men in top hats and tailored suits, and corseted, bustled women.
There’s also the might-have-beens of steampunk. The anachronistic technologies, placed in the context of the age of science, reason, optimisim, and hope–which was simultaneously the age of imperialism, oppression, elitism, and racisim–creates a plethora of new and fascinating alternate histories to explore and inhabit.
But another, significant part of the appeal of steampunk is that of permanence. In a world of mass-produced, assembly lined, injection-moulded products, the process of steampunking transforms them into something hand-crafted, beautiful, for the ages. Steampunk speaks to that desire for the special, the unique, the heirloom, in the midst of our culture of disposable everythings.