It's definitely not just nostalgia or something. As has already been noted above: films nowadays really do go for an absurdly frenetic pacing. This is not coincidental: people simply no longer learn to write properly. There's a whole bunch of "writers" out there who couldn't identify a solid character arc if you clobbered them over the head with it.
I would not be the least bit surprised if that was due to studios hiring younger and younger scriptwriters. Not to shit on twenty to thirty-year-olds (I am one) but there is a certain sort of wisdom that comes from experience, and you only get that experience by meeting new people and trying new things.
When Hollywood was at its best, it was stocked with people who had actually done stuff for a living that wasn't filmmaking. Actors, writers, directors and gaffers had fought wars, flown planes, dodged bullets, and sewed wounded soldiers back together. They worked hand-in-hand with honest-to-God cowboys who either tamed the Wild West or knew the legends who did.
Now the all of the people with input into the story making have only ever made movies. Their career path is uniformly a straight shot through high school into a college where they partied their brains out in search of a soft degree, after which they hung around doing scut work and dead-end jobs in Los Angeles until they finally got their lucky break. All of the people who have actually done something for a living are technical consultants who get hired on to be ignored.
If you've ever say through a movie and been blown away by all the technical mistakes, consider that Hollywood writers make the same mistakes with characterization for the same reason that they get guns and medicine wrong.
That's not to mention studio micro-managing, which is on the rise again, and results in complete nitwits from over at corporate making decisions they have no business making.
This is a major problem too, and might even be a bigger one. In fact, a friend of mine has pointed out that video game stories turned into dogshit when video games became massively profitable, and the corporations moved in. Executives don't know storytelling, so they rely on metrics like "does this have x" or "how much of the test audience looks away from the screen in this one scene?"