This is an interesting article on io9. I'm not sure about the parenthetical in the title though. Other shows and series have done some of them, and in some cases done them better, but none of those have done all of these together.
Scripts by the biggest science fiction writers of the day This was really the exception, yes there were a few scripts by such, but other times it was just story ideas. The majority of Trek writers weren't big scifi novelists. Pushing the outer edge of diversity More (at best) staying up with the standard diversity of the media of the day. In many ways Trek fell behind society, and either had to play catch up, or simply didn't try. Heroes whose limits are partly self imposed How would this be different than a cop show, where the heroes are bound by regulations, procedural rules and legal restrictions? Plus the prime directive (especially in TNG) was a get out of jail fee card to exercise ethical/moral cowardice. Trying seriously to portray people who had left barbarism behind Kirk: "I will not kill ... today." Trek (imho) was at it's best when it depicted average people in the future. Picard's condescending attitude to the side, there's not a single person in the 24th century who's better than people who can be found today. There are good people and bad. Characters who age realistically As opposed to Jean Luc Picard, movie action stud. With kung fu grip and optional dune buggy. .
Am I the only one who doesn't love Richard Matheson or Harlan Ellison? And it's true that all the literary writers only wrote very few episodes. But I agree that the casts were, though probably not revolutionary, still (especially for the times) pretty impressively and uniquely diverse. I also agree that the restrictions on interpersonal conflict and character flaws led to a lot of creativity in the stories and made what conflict and flaws there were more interesting. I think even most of the good cop shows have their heroes often ignoring their legal restrictions and very rarely getting in trouble, let alone having personal regrets, and the few times they get in trouble for violating restrictions feel arbitrary. I think most agree that that was Trek becoming less unique for the worse.