I think in reality the subjects of films have not to do with the fate of technology or the beliefs of most humans but what 18-40 year old men will pay $20 to see. Your comment holds more water when applied to futurist films but literary futurism consist almost exclusively of cautionary tales and even they have more to say about those who weild technology than the tech itself. So part of the issue seems to be that the genre of futuristic speculative fiction is almost exclusively dark in tone. This has as much to do with marketing costs and audience expectations as anything else I expect. We don't watch Mad Max and The Matrix because they are more plausible than a film about a world in which technology heals society but because it is more compelling entertainment. Works about the future reveal our feelings about the present more than anything imo.