Frederik Pohl has begun blogging about his experiences with Gene Roddenberry. One interesting thing is that Roddenberry not only pitched ST to unimaginative studio execs by describing it as “a kind of Wagon Train in space,” but he also promoted it that way to fens. That's an odd approach to take, telling fans of one genre (science fiction) that they should watch your show because it's like a completely different genre (western). I'm sure Pohl wasn't alone in his reaction: "That didn’t awaken in my soul any desire to see it"
I know most sf authors of the time took a dim view of it. I've heard an interview with PKD where he sneers at ST because it was doing the kind of stories he was writing back in the 1950's. Harlan Ellison, who actually wrote for the show, was always very dismissive of it. Even today authors like Charles Stross will tell you he hates Star Trek.
And while it's true that ST wasn't particularly innovative and contained too much technobabble, unlike most popular Hollywood franchises it features characters who are engaged in scientific exploration. As fun as Star Wars is there are no scientists in it. But even shows like Voyager had the captain giving impassioned speeches reminding the crew that they were first and foremost on a scientific mission. I think we could use more TV like that.