Those are all horror to me. I was just watching Starship Troopers, my favorite sci-fi film and even it's end degenerated into gratuitous horror instead of smart sci-fi. Did we learn anything about the bugs or ourselves in the end? No. i would like to rewrite that ending to be more thought provoking, thoughtful and insightful. I guess it's a matter of intent and the disgression of the programmers of sy-fy, etc.. Once again though we're talking about the lowest common denominator (demon eater) here $ and ratings.
I don't know. Any definition of sf that excludes ALIEN, THE THING, and H. G. Wells (!) seems a little restrictive to me, not to mention divorced from the entire history of the genre.