Why do science fiction films portray the future in a negative way?

Oh, dude, Science Fiction films love to be all dramatic and stuff. They're like, "Hey, let's show the future as a total disaster because it makes for a more interesting movie." Plus, it's way easier to come up with cool special effects for a post-apocalyptic world than for a utopian society, you know? So, they're just like, "Let's make everything go wrong in the future, it'll be a blast!"