A big reason why Star Trek TMP didnt pull off Star Wars success
We all know the story, Paramount were umming and arring how to bring back Trek. A low budget movie or TV series before finally deciding on a 2nd tv show (Phase II), sets were built, scripts commissioned(some later used for TNG during a writers strike) everyone signed up bar nimoy,.. then SW came out and Paramount wanted a big proper movie scrapped the series and hired big name director , and it came out and was hit by negative reviews. It made 140m worldwide to SW's 700m (or whatever it did at the time minus all the reissue box office). TMP was still success just not on the level of SW
But why? Why couldnt Trek do what SW did? Sci Fi fans had been gagging for more Trek over the past decade and here it was in a no expense spared movie! SW itself was even part influenced by Trek (along with a mish mash of other stuff: LOTR, cliffhanger serials, Flash Gordon, Joseph Campbell, Kurosawa, religion etc)..
Well a big reason is SW tapped into the youth market, it was fun, FX like no one had seen since 2001, action packed like a comic book, and all the instant iconic stuff The Jedi,The Force, Darth Vader, ObiWan, The Droids, Millennium Falcon, XWings/Ties, DeathStar, lightsabers, etc,etc but at the centre of it all it had YOUNG, HOT, NEW stars in Hamill Ford Fisher for teens to obsess over pin up on bedroom walls,. Trek TMP had all the cool tech and mythology stuff of its own universe (like Wars) but had middle aged Shatner, Nimoy etc. yes they were YOUNG and HOT back in the 60s when they were early/mid 30s but here they were approaching 50 and despite bring in decent shape were looking every one of those years. To counter this the filmmakers realised they needed young blood so introduced two unknown young hot potential future stars (like Hamill Ford Fisher) in Stephen Collins , Persis Kambatta, ok all good fine but they SHAVED the head of the gorgeous Kambatta completely removing her hotness appeal and Collins was very bland in the role. (notice for the sequel they repeated the same set up but made sure to keep the hair on the hot actress!) so that added to the boredom/slowness/adultness of the movie (that would really only appeal to the nerdy hard core fan base) there was just nothing really to attract the young audience (teens, 20s) like there was with SW.
Look at how huge Titanic became, yes it was a mega budget version of the legendary tragedy with state of art FX, replica of the ship, great music/song but at the centre were two young hot stars for younger audiences to go nuts over (Leo became a phenomenon like a modern day young Elvis). And for when it came time to reinvent/reboot/prequalize Star Trek they obviously made sure to get young hot stars in the iconic roles (a young Brad Pitt like Kirk, the strangely attractive Sylar from Heroes as Spock, a hot Beyoncé like Uhura soon to be star of Avatar) and as a result ST09 became a bigger than expected hit esp in the states one of the biggest movies of the year.
So ultimately ST:TMP really needed some hot new stars to counteract the middleage-ness of the original actors, yes Collins and Kambatta but ffs keep her hair! And make the movie more fun, action, colour, sexy. more like the TV show. and probably would've made double what it did which would still have been about half of SW box office (yes they more or less did that for the sequels but the damage was already done with the 1st film)