Although shows aren't mainly about romantic relationships, those are always fun storylines to explore. Some couples on shows get together almost instantly, and it turns out great. But some decide to take the more painful route and do the slow burn ship process.
This is basically when two people take forever to get together. They have all these moments that make it obvious that they care for each other, but neither one of them does anything about it.
It's cute but agonizing for the fans that want them together. However, when they actually do get together, it's the best feeling in the world for fans.
This is a route that writers love to go with. They know that the anticipation will keep fans watching, knowing that eventually, the couple has to end up together. As someone else who enjoys writing stories, I understand that aspect.
One great example is Jim and Pam from "The Office". They took seasons to get together, even though from the very first season it was obvious of the feelings Jim had for Pam. It turned out great, but those first few seasons of waiting were agonizing.
However, despite the fact that many slow burn ships turn out great in the end, some just simply never happen, or they seem to take too long to do so.
Like in the CW's "The 100". One of the biggest ships of that show is the two main characters: Clarke and Bellamy. Since season 1, they have had a rollercoaster of friendship, going from disliking each other to being the only one the other could rely on.
Over the course of 6 seasons, Bellamy and Clarke have experienced practically everything that normal slow burn relationships do. There are plenty of scenes where everyone around them called them out for caring about each other more than anyone else. There are times when they risked their lives to save the other.
However, the only things the writers have given the fans are a few dramatic hugs over the years. And the fans keep holding out hope because the way Bellamy and Clarke act with each other seems like they're going to end up together. But the writers know this, and they keep giving us these tiny scenes that give us hope, but never actually deliver.
It's getting to be too much for some fans. After 6 years of waiting for these characters to admit the obvious, there is still absolutely nothing to go on. They write lines that platonic friends wouldn't say to each other.
Also, the actors are married in real life, so there's definitely not a lack of chemistry between them.
As I said, shows are not only about the relationships that develop on there, but they are some people's favorite plot lines and stories to follow. So when it is screwed over just because the writers are too afraid to actually just make them a couple, it gets annoying.
If shows keep up with this tactic for too long, they are probably going to lose some fans soon, those who realize that the writers are only baiting the fans with this fantasy to keep them watching.