The genesis of Steampunk is obviously with the actual Victorian science-fiction writers.
As H.G. Wells imagined the future, this movement lives it. The wild literary technology expressed by Jules Verne finds reality in Steampunk's arts and crafts.
Literature is important here. The whole movement began in works of fiction. Minds continuing the vision set by their Victorian predecessors; and applying what actually happened on top. It became a rich seam of wondering what could have been, had Wells and Verne seen truly. The worlds that they penned felt so real that they eventually seeped from the page into wardrobes and homes.
In terms of counter-culture, Steampunk gradually gained credence since the 1980s, creeping through the '90s to finally have its day now.
There's a deep psychology here. Steampunks look around themselves to a mainstream age of sameness. Clothes off the peg keeping everyone following the groove of narrow conformity.
Everyone looks the same, dresses the same, wear the same hair-styles. They buy (and then discard) the same items, furniture, cars, 'phones, gadgets, all because stores and media tell them to. Like sheep being herded into the same restrictive pens.
It's banal! It's boring! It's mass-produced goods bought to break or fall out of fashion a short while later. Where is the pride in it all?
Steampunks create their own clothes and personal items. The more skilled do it from scratch. The less proficient take what's on offer, then add their own decoration, or take off the lid and expose the innards. All is different here. It's creative and it's exciting. It makes people want to tell you what they did; and show you the results.
And above all, it's very, very elegant.