Fast 5 worked, very well as a movie, which lead people to the understanding that these films might be quality. If you watch any of the others you find this to be far from the truth. However the momentum from 5 is what is pushing Fast & Furious 6, both in terms of audience perceptions and critical reception as well.
5 benefited from two things;
One, most of the audience had never seen or had totally forgotten any story from the previous films. As a result during the horrendous dialogue scenes that push forward characters archs, instead of focusing on the piss poor writing and less then stellar performances the viewers are playing catch-up in their minds trying to put together the pieces to understand the basic thread of information and motivations. This distraction leaves the audience with the feeling that they weren’t bored during those lousy scenes because it was making them think, which is find and dandy except you aren’t thinking you are trying to remember why you care. But then the scene ends and the next action scene begins and you realize you don’t give a damn anyway. When viewing this film again it becomes apparent that any scene that doesn’t involve someone fighting or driving a car is almost unbearable.
Two, insane action set pieces. Wow, just wow. Stealing cars from a moving train, involving blow torches custom cars, a cliffs edge, etc. This scene off the top of the picture is stellar and ludicrous and sets the film’s tone. It is so much fun anyone would be willing to sit through an hour of boredom as long as there is another scene to rival it. Which of course there is which is what makes Fast 5 so good. Rarely does an action film of this caliber deliver upon much. The finale of the film The Safe sequence, which is easily the most balls out insane chase scene since The Matrix Reloaded, is filled with wtf, and fun holy shit moments every minute or so. For the entire sequence the audience is constantly reacting vocally, cheering, hooting, etc. as the film delivers upon promises made in the tone setting of the train scene.
Since these scenes fall in the beginning and end of the movie the audience walk out thinking they saw something incredible cause as a wise man said, if you give the audience a good first and last 5 minutes what happened in between wont matter. And its true till you try and watch it again in; which case you are glad you are at home and can just skip to the parts you want to see.
Now I trully believe that because of these two reasons Fast 5 was a fantastic film experience. And the audience wants that experience again, so we all bought our tickets for Furious 6, which wasnt very good. It had a good tank chase in the middle, and I cant remember anything interesting about the beginning, and the end was okay but delivered few wtf, and holy shit moments compared to the safe scene in 5. Ultimately not a spectacular film going experience.
Benefiting from expectation, people walk away from Furious 6 enjoying themselves because thats what they wanted, and so they tell themselves that it was a better time then it was. In reality they checked their iPhone at least a dozen more times during Furious 6 then they did during Fast 5.
Lastly, the success of these films I believe is hinging on one other intangible factor, the Hollywood cycle. I think we are entering a return to the more basic Hollywood Action Film which has taken a back seat in the last 10 years to the Fantasy Films. I mean everything from LOTR to the Avengers are fantasy films, based on the idea of characters who can do things human’s cannot. I think (and frankly hope) that audiences are coming back round to a desire to see “real people” push the limits of their human abilities. The Fast and the Furious film deliver just this. I may be wrong on this last point but its the feeling I have, and what I want to see, as I have had enough of superpowers and silly costumes for the time being.