Is steampunk a single genre?

I've been dipping my toes into steampunk--as a reader, not a writer--for the last year or so, just trying to see if it's something I enjoy reading, and if it's something I thought I might be able to write at some point. If I ever do write steampunk, it will likely not sound like a lot of other steampunk prose fiction out there, because I don't think I could pull off the pseudovictorian prose that a majority of the steampunk I've read affects. I have encountered a few examples, though, where the steampunk is all about the juxtaposition of modern contrivances with low technology. I could see myself doing something like that. On the other hand, I have no great interest in writing about England, but I could have fun writing something set in the United States or in Latin America--or in some totally unheard of land.

The more I read, though, the less convinced I am that all the things being bundled together to show how trendy steampunk is are in fact one genre.

(I'm no expert of course. I think I've made this point before: My blog, my aimless and possibly inaccurate rambling. I'm just thinking "aloud" here. If my facts are wrong, feel free to tell me where.)

I perceive of steampunk as being inspired by H. G. Wells and Jules Verne. The Victorian overtones in steampunk are in homage to those two authors. For them it wasn't an affectation, though--it was their era. (Of course, Verne was not a subject of Victoria. Presumably the same stylistic choices that were common in English literature were common in French, or perhaps he was simply translated that way.) I've actually seen Verne and Wells classified as examples of steampunk, but that seems patently ridiculous. They wrote science fiction. Their science fiction bears the stylistic and technological stamps of their societies, but these are not self-conscious homages to an earlier age.

When it comes to fashion, what is the difference between being steampunk and being simply quasivictorian? Goggles? When people mod their computers or whatever, that is pretty clearly steampunk, because what they're creating is a Victorian-inspired version of something technological that never actually existed in that era. This is what a Victorian computer would have looked like if there had been such a thing. That seems pretty quintessentially steampunk. But if we're just talking about top hats and waistcoats and pocket watches and monocles, where's the steampunk in that?

A lot of writing on steampunk I've read refers to the original Wild, Wild West as some sort of proto-example of the genre. I love Wild, Wild West as much as anyone, but here, specifically, is where I am most unconvinced. I'd say pseudo-historical action tales including technology that didn't exist in the period in question has a long history as a trope. In how many Indiana Jones or Allan Quartemain type movies have we seen some millenia old native treasure trove feature automated devices putatively powered by carefully counterbalanced stonework or by underground streams or whatnot? Should we label these something like "stonepunk"? I don't think so because I don't think the creators of these movies and shows had it in mind to meld science fiction with historical settings. Rather, they had a particular setting in mind, and they didn't want to let the technical limitations of that setting interfere with the cool eye candy they wanted to pull off.

I'm not convinced that Brisco County, Jr. counts either, because Brisco actually is a time traveler. That makes this as much a steampunk story as A Connecticut Yankee in King Arthur's Court.

What it all comes down to for me, I think is this: the literary steampunk I've read is largely based on imagining what could have been if earlier societies had managed to invent high tech items based on the technology available to them at the time. It envisions societies substantially affected by these inventions, though still recognizable historical. The nonliterary examples I'm familiar with seem to be more about style--James Bond in the old west, say. What would a fan of the Will Smith movie, or of the Jackie Chan Around the World in Eighty Days, make of the Victorian prose, "gentle reader" asides, and infodumps of written steampunk?