Doctor Who is different from most other fandoms (the closest analogue is superhero comics) because rather than being a work created by one single creative team that will be get cancelled when they get fed up with it it's an open-ended work which has traditionally had regular complete changes in creative team and wide shifts in style and genre between different creators. Hence people who object to things that the current creators are doing will often still keep watching it because they hope it'll get better again once the next creative team takes over and because they're scared to stop watching until that point in case they miss out on vital plot continuity stuff.