Several will say that SteamPunk has two origins. The first is the scifi wave that really got started during the Victorian Era. Which lets face it, the Victorian Era, is about 100 years in our society where technology provided more lesuire time for a greater number of people then in the past. Murder mysteries, sci-fi, children's stories...all came into their own during that time. Jules Verne, H.G. Wells, even Mark Twain all wrote with a science fiction twist.
Take that into the modern area, as early as the 1920's and 1930's when the silver screen presented these stories and the later golden area of scifi after world war 2 with Assimov and other greats. All of that influenced what finally was coined "Steampunk" by a writer who was writting a letter to a magazine some 25 years ago. Which several site as the origin of Steampunk. The first time it was actually named. It's fashion, it's writting style, and for some it's a way of life.
Women and cats will do as they please. Men and dogs had better get used to it.