The survivors of the Poseidon would be rescued and taken to land in Italy and be placed on a train which would go through a tunnel in the Alps, and the tunnel would collapse and everyone would be trapped under the mountain. Irwin Allen cleared his throat modestly. What, he asked, did I think about his idea? It was, I said, a great idea, terrific if not actually stupendous.
But I had a better idea.
Here's what happens, I said. After everybody fights his or her way to the top and/or bottom of the boat, surviving fires and floods and explosions, another big tidal wave comes along and turns the great ship over again. And so the hapless survivors have to retrace their steps!
We see what absolutely nobody wanted to see - Dr. Grant and Dr. Sattler completely split up as she decided to have a family with someone else. Oh yeah, you nailed that one, movie. That's exactly what everybody was hoping was going to happen by the end of the first film. Just like Tommy Lee Jones splitting up with his wife in Men In Black 2, or the orphanage being shut down in Blues Brothers 2000, or all the supporting characters being killed in Alien³, you made one of the most likeable elements in the previous film mean completely nothing. Why don't you just write a big sign at the ending of the first movie saying "You don't like this! You don't want to see this go anywhere! Do not focus on the heartwarming moment we're intentionally focusing on!"?
The original TRON stars Jeff Bridges as game developer Kevin Flynn in the most confusing plot ever summarized on Wikipedia. It doesn't matter, it's all setup for him getting sucked into a computer and having adventures inside its digital fantasy world... Now flash forward 30 years later, to the most unnecessary sequel of all time, TRON: Legacy. We learn that Flynn is incredibly bad at learning life lessons and has gotten his silly ass stuck inside the computer again.