I've been lurking around here for quite a while during the past few days, especially in this thread. I've finally decided to register an account, since I have a lot of problems with this movie and would like to hear others' opinions on it. So far, from talking to my friends, all I keep getting is "it's just a comic book movie, who cares?" and that's really unsatisfying for me...
The problems that I have with this movie fill three pages, but a lot of them are minor points or have already been discussed, so I'll just stick to the main ones:
How does SHIELD even work, at least in the MCU? Who controls SHIELD? Who funds it? Where are its members from? These questions started to become problematic in The Avengers, but after CA2, they have really become huge plot holes. Specifically, the climax with the Helicarriers makes absolutely no sense, as others have pointed out.
1. Who knew about the launching of the Insight Helicarriers?
a) Nobody knew except SHIELD. This is impossible, given how DC has probably the most restricted airspace in the US. Three massive flying ships popping up in the middle of DC, unbeknownst to the Department of Defense and the Department of Homeland Security, would be a major problem.
b) The government knew, but not the public. This is also impossible given the extremely prominent location of the Insight Helicarrier shipyard underneath the Potomac River. If the Insight Helicarriers were supposed to be a secret operation, then why weren't they built somewhere more discrete instead of the nation's capital? There's no way three massive ships appearing over DC like that could happen without notification of the public.
c) Everyone including the public knew. If so, then why weren't there any spectators? For such a grand event as the launching of three Helicarriers, a not-so-mundane occasion, there should be massive crowds lined up to see. But there wasn't anyone around.
2. Who paid for the Helicarriers? I can accept that Helicarriers can fly. I can accept that three can be built simultaneously under an accelerated timetable (even though it can take seven years to build a real-world modern carrier, that is, the non-flying kind). But what doesn't make sense is this: real-world carriers can cost $25 billion to build. I'm assuming flying ones will cost more. So let's say the three Insight carriers cost $100 billion. The US had a huge military budget, something close to $700 billion annually, but most of that goes into maintaining bases all around the world; only about $20 billion of that goes into construction. No other nation in the world spends anywhere even close a quarter of what the US spends on military; so where did this money come from? It certainly didn't come from Tony Stark, whose net worth has been estimated by Forbes to be around $6 billion, hardly enough for just a single Helicarrier turbine engine.
3. How was HYDRA's plan ever going to work? Project Insight seemed to be made up of two parts: surveillance to acquire data on "threats", and Helicarriers to eliminate those "threats", including President Ellis. Let's say Captain America and company never found out about HYDRA's plan, and those Helicarriers were able to start blasting people away. Almost immediately, everyone important in DC, including much of the nation's leadership, would be killed. Then what?
The three Helicarriers would be shot down in a gigantic Independence Day style battle, that's what. There's no way they would have ever gone anywhere beyond DC. Maybe they would have killed thousands, maybe tens of thousands, and that would have been horrible, but there's no way they could have gotten to twenty million. No way. And then where would HYDRA be? They still wouldn't have been in position to take over, not unless they paid off the new vice president or something.
It really feels like the directors and writers wanted an amazing finale but forgot to justify it through the plot, which is a shame, considering how awesome the movie is, otherwise. The excuse "it's just a comic book movie" only goes so far. It works for little things like how Sam was able to avoid getting hit by any anti-aircraft fire or how he was able to deploy his parachute at the last second. It even works for things like Helicarriers being able to fly. But it doesn't work for major considerations like the the inconsistencies of the entire SHIELD organisation.