Nirth: Can someone enlighten us?
Didn't we already have this discussion little time age ?
Sequels often redefine the events of the previous movies, their characters, and their implied endings. They fill blanks which emptiness were a part of the first story's quality. When they do it badly, the response is to "ignore" the sequel. But this is a bit artificial, and fake, like ignoring the following chapter in a book, or the following volume, or the following episode in a series. The character's general, collective, consensual definition, is shaped by the whole series, so, you end up alone on you little island of denial, instead of sharing a story with the rest of its public.
You can choose -if it bothers you- to imagine that Holmes died for real in the Reichenbach falls, or that Ian Malcolm died in the Jurassic Park, or that James Bond lived forever married with Stacy, or whatever, if you decide to interrupt a story at the point where you want it. But it's a divorce from the biography of the characters as the authors resumed it, and as the public then knows it. If you discuss Holmes, you're just "wrong" claiming that he ended his life with Moriarty. It's not (collectively) true anymore. You can just go "for me, he did", ti which people can answer that yeah whatever, and go discuss Conan Doyle's work elsewhere.
Of course, this depends a bit on the legitimacy of the sequel (for instance, I think most people simply ignore "Casablanca 2", some works keep consensual unicity). But generally, the relation to the story is changed, as some specific "personal interpretation" is suddenly required. It's not nothing, it is an annoyance.