How much input should fans have of the franchises that they love? The companies that own those franchises, like Star Wars, Star Trek and Doctor Who, have the right to produce whatever they choose without fear of legal backlash by viewers.That said,those companies count on fans to bring in the money.
When the movie trailer for Sonic The Hedgehog was released to the public, the public to respond with 'take it back'. The powers that be listened, made changes, and the movie's now a hit.
Then you have the folks at companies that figure that since they're in charge of the franchises, the fans will eat anything up, and beg for more. But then the fans strike back.
Once case in point, Star Wars The Last Jedi. Fans waited with baited breath to see how the cliffhangers they spent two years waiting for would be resolved. And the choices the filmmakers made left many fans feeling betrayed, then then let LucasFilm know it in no uncertain terms. LucasFilm responded with its own criticism of their fans. And this led to a back and forth blame war between the two factions since. The last film in that trilogy tried to please both sides, and pleased neither. I didn't pay much attention, since the story ended at Episode Six for me.
A second case in point, Doctor Who. Recently the producers decided to alter the main character's backstory, actually answering the question, 'Who is The Doctor?'. And fans did not like the answer. Some blame the actor in the role. Others blame the showrunner, and the lack of science fiction writers for the show. Personally, I tuned out a Doctor or two ago. And apparently the majority of the audience has too, with the current series season finale garnering low viewing numbers.
And then there's the state of Star Trek, which... is too painful for me to think about right now...
Wow. I've left more than a few fandoms. I'm either really old or just ahead of the curve.