For the first new live-action Star Trek in 10 years? No. Modern audiences (iow younger people who weren't alive back in the '70s) have no idea what it was like back then... syndication on TV was all we had. There were no VCRs to record episodes, nobody was selling episodes, and while there were a few novels and the Blish books around, for the most part if you wanted new Star Trek stories, you had to either buy fanzines at a convention or write them yourself. People got their information from print magazines, for the most part, and I remember pouncing on every scrap of information I could find about TMP. I remember my dad - more of a Who fan than a Trek fan (years later, after I introduced him to Doctor Who) - coming home from working up north, but as he passed through a store somewhere he spotted the novelization of TMP and bought it for me, simply because he knew I liked Star Trek. And then he took me to see it when it did come to town. We didn't have umpteen different versions of Star Trek, to pick and choose our favorites. There was only one, and the idea of having anyone other than the original cast was not what most people wanted. It would have been pretty damned boring. I wouldn't have cared half as much about the events of TWOK if Chekov hadn't had the expanded part he got, and I'm one of the people who would have loved a "Captain Sulu" series. Are you saying that the reason there were only 6 TOS movies is because Shatner and Nimoy didn't want to make any more? And what would make these people so compelling that people would have welcomed them as acceptable replacements for the original crew? And which version of Saavik? I loved Kirstie Alley's Saavik. Robin Curtis was... let's just say that cardboard has more personality than her Saavik exhibited. But Christian Slater? He would have made a fine addition to the cast (as a secondary character). He looked like a natural in Star Trek VI. Without the first two movies in that arc, it's doubtful that the fourth movie would have been about the whales. But yeah, I always wondered how she ended up getting along in the 23rd century. Planet of the Apes, James Bond, Star Wars (had always been planned as a series of at least 9 movies)... I'm probably forgetting others. No. It would not be glorious. It would be every bit as awful as the other nuTrek garbage is. "NuKirk-unit! Disclose the information!" And instead of the scene in Sickbay in which Spock reaches out to Kirk and explains V'ger's self-questioning of "Is this all that I am? Is there nothing more?" we'd get nuUhura stomping in and whining at nuSpock about their relationship and telling nuKirk, "Not now, Captain" and he'd meekly shut up instead of questioning nuSpock about what he'd discovered in his mind meld.
Those were the only three I could think of at the time of my post (although it occurs to me now that most of Superman II had been shot at the same time as the first one, so that was planned to be a series from the outset). Again, pretty rare when compared to the number of film franchises we have ongoing today - especially when you factor in that Planet of the Apes had been dead in the water for 5 years at that time after consistently diminishing box offices (and budgets) and we were still six months away from Empire Strikes Back, so Star Wars was still establishing itself as a series. Star Wars was just starting to establish the idea that a big budget sci-fi film franchise could exist, so there was no reason for Paramount to automatically assume Star Trek could support more than one film.
The first Star Wars worked as a standalone movie, but my point is that Lucas had planned for it to be part of a series of movies. Fortunately for him and for the fans, it worked out (some of the time).