First of all I need to get a few things straight: I don't read comics but I have a general understanding of certain storylines and characters. I sincerely believe that Marvel hasn't released a "bad" movie yet - just movies that are worse than the others. And finally what I did like about this movie, I LOVED. Anyway, you asked why some people do not like it, so I will only explain why I don't like it and not the few bits that I do.
So let's start with the "Civil War" part of the movie thats called, you know, Civil War. I am completely aware of things that happen behind the scenes of these movies - things that most movie goers, and even comic lovers aren't. I know that Marvel sold off characters in the past and have been trying to require them, which is why certain characters aren't in their movies - meaning I know how Spiderman came into this movie and why he had a very small, cameo-like role. I know HOW and WHY the Civil War storyline was integrated into this film, and I understand that it was intended, and IS a Captain America movie first and a Civil War movie second. However, the Civil War aspect of this movie was completely tacked on, went nowhere, and ultimately only really served to lengthen the runtime because it added virtually nothing to the actual story being told here. The Airport fight was VERY fun, but you could take it out of the movie and noting would change. At all.
Speaking of the actual story being told, lets talk about the real story here - being the Captain America events. Namely the Villain. Let's talk about the villain. This villain, Zemo, was a complete and utter middle finger to fans of these movies on all fronts. I UNDERSTAND his character motives; I got where he was coming from, his logic was sound, but everything else about him was a waste of time and completely ludicrous. This is a normal man who managed to outwit the Avengers. Sure, this normal man had special training but at the end of the day he was just an average joe looking for some vengeance. You serious right now? The Avengers are completely torn apart by the workings of a single man? Oh wait, I'm sorry. They weren't torn apart by a man - they were torn apart by each other. Again.
That brings me to my next topic point: this is the third F*cking movie where the main goal/plan of the villain is to have the Avengers fight each other. It was a gimmick that worked in the Avengers because that was the whole premise of the movie. But in Age of Ultron, what was Ultron's first plan of attack? Scarlet Witch, have them fight each other. I rolled my eyes then, and thankfully it didn't work out that way, but I sure as shit rolled my eyes when we saw this same old cop-out for the THIRD time. Because that's what this is at this point - from a story telling perspective, this is a cop-out. It's lazy. Don't be surprised if in Infinity War everyone starts fighting each other again.
Look at that, yet another segway! Infinity War. This is the event we have been building towards since the Avengers. Its unknown if this was Marvel's end-game from the start, but it sure was as soon as they released the Avengers. We have had 12 stellar movies before Civil War. A dozen films setting up the world we've come to know. Now its time to go bolder, to start exploring more and more, to really start introducing the larger storyline ahead for our heroes. Too bad Civil War does NOTHING ABOUT THIS. This is actually my BIGGEST issue with Civil War - its not necessarily the film itself. Despite everything you just read, I could have easily overlooked EVERYTHING if Civil War did anything to address the larger hand at play. Look, if we just wanted film after film of superhero films with an occasional team up then thats fine. But that is not what Marvel set out to do - that is not what we were promised and that is NOT what we have gotten in the past. What Marvel set out to do was nothing new, but it certainly was ambitious and it certainly paid off - Marvel set out to create a Cinematic Universe. You may have heard this term, but what does it actually mean? Well in theory, it essentially means being able to create multiple films that all interconnect which allows the studio to tell a much longer, larger story throughout individual components. Very similar to a TV show, which has an overarching plot told over the course of seasons at a time. Same concept, just in film - we were promised the build up to Infinity War, which understandably takes time to set up; you need to introduce the entire universe of characters, make us care about everyone, introduce us to the stones, etc. Civil War is the THIRTEENTH FILM. Thirteen. Infinity war is coming in TWO YEARS! We will be getting NINE MOVIES crammed into those two very short years, and Civil War still is acting like its own isolated film. You could watch Civil War first out of the entire film slate and still be able to keep up with things. We should NOT be doing this at this stage, every film from here on out SHOULD be all connected and really be pushing the Infinity War story line. Two years left, and we haven't truly been introduced to Thanos or any of his shenanigans. And yes, I know that Thor 3 and Guardians of the Galaxy 2 will likely have a hand in that, but Civil War should have also taken bolder steps to really pushing the story forward.
Which brings me to my final ranting topic point: the lack of balls this movie had. Now I already kind of sort of touched upon this in the rant I just did above, but what equally pisses me off about this film is the lack of risks it took. This is a very, VERY easy going film, that touches upon some subject matter that almost DEMANDED for some serious change. By the end of this movie, NOTHING had changed from the beginning. Rhodes was crippled, but Tony gave him a fancy new robot-leg thingy, kinda similar actually to Batman in The Dark Knight Rises, so he'll be coming back in some way. Look, I could go off on a whole other essay analyzing the strong character motives and character story arcs this film told; specifically the final fight between Tony, Steve and Bucky. But just to keep it short, that fight was the true highlight of the film. The Airport fight was fun, but it had zero content underneath it. The Tony v Cap fight, now that was truly amazing because of everything that fight stood for, and why they were fighting to begin with. And honestly, the fact that no one died during that fight was the biggest waste of potential any of these films have EVER had - and thats saying a lot considering how disappointed I was in Age of Ultron. Moving beyond that one fight (as again, I could write for days on that fight), by the end of the film Tony is bruised up, Bucky puts himself on ice (which is another aspect of this film wasting your time), the Avengers are all in prison but its ok because Steve busts them all out and sends Tony a letter saying if he ever needs them they got his back. Everything tied up in one nice little bow. Disappointed isn't strong enough of a word to describe how I felt at the end of the movie.
This is more or less how I feel about the movie in regards to why I strongly disliked it. For anyone who actually read all that, you deserve to be given rep points so let me know and I'll happily rep you for reading my opinion. And again, I feel I should reiterate: I ranted for days above, but what I liked about the film (yes, believe it or not I did actually enjoy a lot of this film) I LOVED. Namely, everything on a technical level of this film (the acting, the writing, the directing, the cinematography, the choreography, etc) was damn near flawless. Its just the story, the story telling, and how they didn't take any risks that gets me so frustrated with this film.