Well fan is short for fanatic but in fairness, some of us are more rational and objective than others. You have some of us that can objectively criticise a movie, book and game, even if it has our favorite monster in it and you get some that will absolutely love the worst movie/book/game ever just because it has their favorite monster in it.
Though they are entitled to their opinions, its not good to get into a debate with someone who refuses or is actually incapable of being objective and looking at things both ways, a lot of nasty arguments come from that. I can understand why some would call them fanboys even if its done with the intent to insult, because in many ways "fanboys" (and I mean this in terms of the unobjective, entitled, think the franchise belongs to them kind of fans, and not simply the overly passionate hardcore fans) really do ruin things for others. They can make forums a nightmare and they can be particular venomous towards those who worked on the projects, simply because things didn't go their way.
The way I see it, being a fan of something doesn't mean you have any rights towards the franchise nor do you get to put down others. We should instead be united in our shared love for something even if we have different interpretations.
Back on topic, I doubt that Alien 5 or Alien 3.2 will be made anytime soon and as much as I didn't like the direction Scott went, I want to see him finish his trilogy, see where David goes and put a definite end to it.