The entire cyberpunk genre is about corporations destroying society and the planet for profit and is near-future sci-fi. Dune is about how human nature doesn't change, the same revolutions occurring again and again over thousands of years, with humans always being on the verge of self extinction and the only escape being to destroy civilization so hard that any conflict will always leave survivors that have had no contact with anyone else in millennia. Hitchiker's Guide to the Galaxy presents a world where the entire universe is utter chaos, worlds can be destroyed by a clerical error, and cosmically powerful beings do random things for shits and giggles. Starship Troopers, Warhammer, and Starcraft depict humans becoming the bad guys at an interstellar scale.
So, no, sci-fi is not inherently hopeful.