You'll have to explain that rather that just state it flatly and expect it to just be accepted. SW simply established a popular formula for sci-fi, but it still doesn't define what a science fiction film has to be. SW was a straight-up adventure story with a measure of action and pacing. It was essentially a tip-of-the-hat to old sci-fi serials and pulp stories. And there was little depth to it either. Ironically the core of SW can be traced right back to E.E. Doc Smith and Edgar Rice Burroughs' John Carter stories. The irony, of course, is that John Carter eventually made it to film long after SW and JC seemed (to some) derivative when it's actually the other way around. There was a spate of SF oriented films coming out in the '70s and '80s and they shared some elements and also could be distinct from each other in other ways. SW wasn't the only successful one, but it's one that doesn't have a lot of meat-and-potatoes to it. If anything SW (along with Jaws) began the formula for the block-buster feature rather than defining the formula for successful sci-fi---make it slick and not necessarily deep. Abrams' Trek followed the SW formula exactly. Make it slick and flashy and dumb it way down. But that doesn't mean a sci-fi or science fiction film has to be done like that.