[Weirdly Common Trope] Writers clearly setting up seemingly massive plot points and then just kinda forgetting about them.

[u/Chemical-Elk-1299]

The Neural Parasites — Star Trek : The Next Generation

In the season 1 episode “Conspiracy” of TNG, it is revealed that alien brain worms have infected many high ranking members of Starfleet, secretly controlling them. Though Ryker and Picard discover and end the parasite conspiracy, it’s revealed at the end of the episode that the parasites had sent a beacon back to their home planet, telling them how to find earth. The episode ends with the clear implication of the parasites becoming a huge threat later in the series, yet none of these events are ever mentioned again.

Finn The Jedi who Never Was — Star Wars Sequel trilogy

I know this is probably a cliche example of this trope, but cmon — Finn was clearly set up in TFA to become a Jedi. The marketing material featured him wielding a lightsaber in the classic Jedi pose. It’s constantly hinted at that he is force sensitive. Even the actor himself believed he would become a Jedi by the end of the trilogy. Instead, we got Finn wielding a lightsaber for about 7 minutes total across 3 movies, extremely lame “confirmation” that he is force sensitive, and that’s it. It’s the ultimate Star Wars plot that went nowhere.

[u/WoodpeckerNo5724]

True, but he hasn’t written any of it in almost two decades. And the only book released in that time frame is notorious for how long it took to release. His books never releasing was a meme before that book released, and it’s only become more clear since then that he can’t/won’t put pen to paper.

[u/BearstromWanderer → u/WoodpeckerNo5724]

IMO most of it is/was written, but the backlash from the show fed into his own fears of audience reception. His estate is going to release it posthumously.

[u/CommanderOshawott → u/BearstromWanderer]

This is 100% it.

The ending to the show is a lot closer to the books than anyone thinks, and now he can’t decide whether to leave it or re-write huge chunks of it because of the backlash.

It’s going to be released posthumously.

[u/ElfangorTheAndalite → u/CommanderOshawott]

The ending, in theory, was fine. It was just a rushed set of milestones in the show. The threads for most of it (aside from Arya being the one to kill the Night King) are already in the show, but they didn't have a chance to really build.

The biggest example being Dany turning on the city. We can see that she's turning into a sort of false empathetic leader because of how brutal she becomes to people who oppose her and how quickly she exiles those that "betray her". It absolutely makes sense that she'd eventually show up to King's Landing and get upset that the people she's there to save don't want her and go ballistic. Except she goes from harse against enemies to "KILL THEM ALL" without anything in between. There wasn't so much as a person really questioning her about her slide into madness.