I agree TNG was FILLED with pretentious nonsense, all the pontificating by Picard. The original series was able to do more episode styles than the TNG cast because in TOS, characters were allowed to have flaws. TOS could tell a morality tale, or have a msg and have fun at the same time. I find TNG to be the most dated out of all the series, with its moral equivalence BS. TNG had some really good episodes as well but by the time they got to the movies, they changed the dynamics of the characters to make Picard some sort of lame action hero which he never was on the show. -Chris
Most of this is because Roddenberry was allowed to be writing for TV again in the first place. During the movies with the original cast, he was kicked upstairs by Bennett and the Paramount brass after TMP, which is why the movies were somewhat better while still being Star Trek in form and message (The Voyage Home being the best example, with its plot about ecological issues.) Of course, after Paramount decided there was to be a new TV show, Roddenberry had to be back as the creator. But just because he was a great creator back in the '60s doesn't mean he'll be a great creator in the '80s, and so we got what we got with TNG (as much as I liked it.)