Check out how many times the trailer for Iron Man 3 fades to black. I lost count, but a couple dozen. Not to mention how many fade in / fade outs there are. A trailer that's supposed to get me excited for a kickass summer action movie makes me feel like I'm nodding off instead. Eyes opening, eyes closing... eyes opening, eyes closing...
Iron Man 3, 2013
This is one of those subliminal things that's kept me out of the movie theater on a regular basis since the mid-1990s. I didn't even notice it consciously until I read other people complaining about it. How far back does this annoying style go anyways? I'm not going to exhaustively sample all action flick trailers, but here's one that's just as awful from 7 years ago --
X-Men: The Last Stand, 2006
I just knew I'd find this pretentious gimmick in a trailer for the most over-rated sci-fi / action flick ever made. Although under way by the late '90s, the fading in/out and fading to black don't continually interrupt the trailer. It's more confined to the early part.
The Matrix, 1999
If it was present during the mid-'90s, it was only getting started in a trial-and-error way. Otherwise you'd see it in the trailer for the defining action movie of the time, but you don't --
Someone else can waste away a half-hour checking the trailers for The Fugitive, Jurassic Park, Batman Forever, etc.
The kickass summer action genre only goes back to about the mid-'80s. Looking at two blockbuster examples, you don't see fading cuts there at all.
Rambo: First Blood Part II, 1985
Die Hard, 1988
Man, whatever happened to trailers with quotable tag-lines? -- "What most people call hell, he calls home." More adrenaline-pumping music too, not that plodding orchestral bombast from the 21st century.
All examples show fast-paced editing since they're supposed to get your heart racing in anticipation for lots and lots of ass-kicking. But why is there such a sharp difference between the good action movies, whose trailers do not use fading cuts, and the boring ones whose trailers fade in and out constantly?
I think it all comes back to that unhelpable "eyes opening, eyes closing" feeling you get when you're drowsy. Audiences these days are afraid of getting excited -- it makes OCD control freaks feel uneasy when something or someone else has control or influence over their body. Responding too viscerally = creepy.
This shows up across all forms of culture and entertainment. Dance music today doesn't get your body moving, slang words don't pack any punch, and nobody makes bonfires during the summer celebrations anymore.
People still feel somewhat of an urge to let their primitive side take over, so they'll still watch action movies, but only if the studios can assure them that they won't actually get too excited. Plodding music, flat inflection in the characters' voices, abuse of slow-motion sequences -- whatever will interrupt any excitement before it gets going. The nodding-off editing style of the trailers fits right in with the rest of the tranquilizing techniques of pseudo-action movies.