IIRC, plans for a Star Trek show came first, not a feature film. When SW came out and became a smash, the pilot's script was turned into TMP. Had Trek gone down the route of TV show instead of film, there's a decent chance that it would have failed, like Battlestar Galactica and Buck Rogers at the time.
Besides, prior to that, there wasn't much demand for sci-fi movies anyway. 2001 was more of a critical favorite than a financial smash.
There were plans for a film prior to Star Wars. The cast talked about it on 'Tomorrow' with Tom Snyder in 1976 (youtube link