In the list of actors who didn't hold out much hope for a long-running series, Michael Dorn admitted that he only thought that Star Trek: The Next Generation was only going to run for a couple of seasons. In fact, as mentioned in Star Trek All Good Things: A Next Generation Companion, he actually thought they would be lucky if the series ran three seasons. Of course, the show ended up surpassing all expectations, ending after seven seasons. But it continued on for four more movies.
It was after Star Trek: Nemesis that Dorn realized how important the series' contribution to the franchise had been.
"I didn't think The Next Generation was going to go for very long. I thought it was going to go a couple years, and we were going to make some money. I thought we'd be lucky if it went three years. When it was all over and done with, and we'd done Nemesis, the last movie, that's when it hit me how important our contribution is to the franchise, and how it just is never going to go away."Michael Dorn
Prior to its debut, The Next Generation faced an uphill battle with fans who weren't interested in a new Star Trek without Captain Kirk, Mr. Spock, and Dr. McCoy. They wanted William Shatner, Leonard Nimoy, and DeForest Kelley brought back to the Enterprise instead of new characters being introduced. So it's no wonder several cast members thought The Next Generation wouldn't last very long. There was concern the fans wouldn't embrace the show. Fortunately, that didn't happen, and the series has become one of the mainstays of the Trek franchise.
The third season of Star Trek: Picard brought most of the cast back to the small screen, and its successful ten episodes showed that the popularity of the series and the characters hadn't diminished in the twenty plus years since we'd last since them all together. And now, fans are awaiting news of a potential spin-off of Picard which would allow fans to see the legacy characters even more often. There's little doubt The Next Generation will continue to be a fan-favorite for a long time to come.