I saw quite a few comments in other articles about how fans are lenient with Marvel Studios for inconsistencies in their movies, but tended to be unforgiving when it comes to Fox's portrayal of the X-men. In my modest opinion I think most fans at this point in time aren't as concerned with the X-Men "cinematic universe" not following the comics, as much as with the movie's complete disregard for continuity.
To illustrate this, please consider the following issues I personally have with the "Fox-Men" continuity. Hopefully, this will be also clarify the difference between "DIFFERENT FROM THE COMICS" and "THE CONTINUITY MAKES NO SENSE".
1 - Who built Cerebro? In X1 and X2 it's stated Xavier built it with the help of Magneto but in First Class, Hank (Beast) builds it.
2 - In X1, Xavier tells Wolverine both Jean Grey (Phoenix) and Scott Summers (Cyclops) were among his first students. In First Class there was no sign of them.
3 - We have two completely different incarnations of Sabretooth? The deaf/mute minddless brute in X1, and Wolverine's more eloquent BROTHER in Wolverine Origins. What happened? Are we supposed to believe these two are the same character?
4 - Mystique as portrayed in First Class is quite close to Xavier. Actually, that's an understatement. She's his sister in everything but blood. They grew up together from early childhood (7-9?) and you could see throughout First Class they were very close. Even if she becomes a mutant extremist, even if she prefers Magneto's approach to the future of mutants, in X1 she tries to kill Xavier by tampering with Cerebro with absolutely no hesitation. Magneto himself who doesn't share as profound a connection with Xavier seems to be saddened by their disagreements and actually defends Xavier's contributions to the mutant cause. Mystique? She shows no emotion. No connection was acknowledged in the original movies. Doesn't it seem a bit weird? Just a little?
5 - In X1, Xavier tells Wolverine he met Magneto when he was 17. In First Class they are in their mid 20s? I assume they are because they look older than 17, and Oxford University graduate Xavier is publishing his thesis on mutation. And drinking pints at the pub.
6 - Moira MacTaggert in X3 was a geneticistic and mutant biologist. In First Class she was an FBI agent? Not to mention the time gap... let's say she was 20 in First Class (being generous for argument's sake). X1 was out in 2000.... that would make her an extremely yummy and well preserved 60 year old...
7 - In X2, Beast shows up on TV, and it's clear he hasn't gone through his secondary mutation (blue fur). However, in FC he underwent a secondary mutation? We're talking about 30 years at least before X2. And please, don't tell me it's an Image Inducer. That may exist in the comics, but in X3 when Leech temporarily deactivates Beast's mutation he (Beast) chokes up saying it's been a long time since he saw his own skin.
8 - Let's assume at the end of X3, Xavier transferred his consciousness to his identical twin brother in a coma (codenamed Deus Ex Machina - aka copout). In DOFP he's in a wheelchair again?
But ok, in Fox's universe maybe lightning does strike twice...
9 - In FC Xavier knew that Sebastian Shaw's helmet (later to become Magneto's) blocked his telepathy. In X1, he had no idea how Magneto was blocking his thoughts.
10 - Kitty Pryde's power is phasing through solid objects. If she phases through anything electrical in nature, she short circuits it. However, in Days of Future Past, her power allows her to phase Wolverine through time? Seriously? Wouldn't it make more sense to create a mutant specifically for that?
11 - In X1 both Xavier and Magneto had no idea who Wolverine was. But in First Class they try to recruit him....
12 - In Wolverine Origins you see Emma Frost in diamond form but no apparent telepathic powers. Quite young as well. In First Class, supposedly about 10 years before, Emma Frost is older and telepathic. And for the naysayers, that is Emma Frost in Origins. Her character's name shows in the credits.
I'm not even going to mention Xavier walking after FC as he was paralysed. Getting shot in the back will do that to you. Maybe Fox decided to follow on TDKR's footsteps and someone punched Xavier's back to fix him up. And he'll get paralysed again (maybe for good this time) in DOFP...
The X-Men have enough continuity problems as it is. It's not a matter of not being faithful to the comics anymore. It's simply that the movies contradict themselves. There is no continuity. There are vague distorted reflections of it, but ultimately it all falls apart when you look closely.
THAT is the problem most people have with Fux-Men.
Please feel free to use the comments section to try and explain some of these issues (if at all possible), as well as raise others that may not be covered in this list.
This is my first article, so apologies for any formatting errors. Thanks for reading.