It's pretty clear that Star Trek: Discovery is the franchise's most hated series

Star Trek: Discovery is the most disliked, aka most hated series that Star Trek has ever produced. That's not really in dispute. The series is perpetually knocked for its nonsensical story arcs and unnecessary changes to canon for no reason and even less reward. Some will suggest that it's unfair to claim that Discovery is the most disliked show in Star Trek history, but we have examples to prove this.

If you look at Rotten Tomatoes, they're one of the least well-reviewed shows by fans. The overall series has just a 33% on Rotten Tomatoes, while season one has the highest approval among fans at 49%. It's all downhill from there, as season two had just a 36% approval rating, season three had a 40%, season four had a 21%, and season five currently has a 19% approval among the fans.

Now, people will cite the critic scores all being in the 80s for the most part, but critics are far less likely to be actual fans of the content they're reviewing, making it harder to say whether or not the item in question is in line with what the actual fanbase wants. You could make the best steak in the world, but if you're serving it in an exclusive pizza restaurant, replacing every pizza order with a piece of steak, people aren't going to be happy. No matter how good the steak is.

That's the issue with Discovery. It appeals to some, but most of the fans felt that the show missed the point of Star Trek. Now, you could argue that due to the nature of how Rotten Tomatoes works, some fans were just "review bombing", leaving negative reviews because they didn't like what they showed in the trailer, but the inverse is often true as well. Moreover, a fan, or anyone for that matter, doesn't need to watch an entire season or series of a show to know they won't like it. If a fan sees something that they're so moved by, either positively or negatively, that still counts.

The whole point of posting trailers is to sell someone on the idea that the property in question is good and worth your time. If it doesn't look like it is, you're more than allowed to reject it out of hand. A passionate fan response one way or another isn't to be ignored. It isn't to be dismissed as "trolling" because something doesn't resonate with the core fandom.

More to the point, of all the Star Trek television shows on IMDB, a website that is much harder to "troll", Discovery has the lowest rating of every Star Trek show. The Next Generation (8.7), The Original Series (8.4), Strange New Worlds (8.3), Deep Space Nine (8.1), Voyager (7.9), Lower Decks (7.7), Enterprise, Picard (7.5), Prodigy (7.4), and The Animated Series (7.2) all come ahead off Discovery (7.0).

It's obvious, without a doubt, by any metric you want to measure things by, that Discovery is the least-liked show in the history of the franchise. It was canceled during the production of season five. That's not the sign that a show was "wrapping up on its own terms", that's the sign that the show was no longer viable due to poor ratings and rising costs and needed to go.

Now, Discovery being the least like show doesn't mean it's a bad show. I personally think the writing and plots are atrocious, but it is one of the better-assembled casts we've ever seen. It's not the talent's fault that the heads of the shows made a show for themselves, as opposed to the fandom that has long-lasted their careers.