I definitely think steampunk has a place under sci-fi but wanted to ask before starting any possible discussions.
3 Answers
Steampunk usually involves some kind of alternate history of technological development so it is feels closer to science fiction than it does it fantasy. I don't see a good reason to exclude it.
Steampunk, like the other "punks" is one of those hate-it-or-leave it genres. I like it, and I consider it "on topic" as it tends towards "alternate histories."