Here's the irascible Harlan Ellison appearing with Star Trek alumni James Doohan, DeForest Kelley, and Walter Koenig on Tom Snyder's The Tomorrow Show back in 1976.
An interesting discussion, and I think the convention organizer makes a really good point when he remarks that every episode of Star Trek involved some kind of violence despite its claims to be avoiding that kind of thing. As for Ellison, he makes some trenchant observations, but he's also unrelentingly negative. And given his later much publicized involvement in the Star Trek-ish Babylon 5 his snarky remarks ring a bit hollow. It's left to Koenig to interject some common sense and observe that while Star Trek may not be first rate sf it nevertheless exposes a wider audience to the genre.