The action movie wasn't new by the 1980s of course, but it evolved into this new form, sometimes with talented young (at the time!), daring directors.
Of course not, it was the replacement of western genre. And boy, they did a fine job.
There was many bad movies at the time that we tend to forget, but were many good ones and a few exceptional. But nowadays, it's as many of more crap ones, much less good ones and nearly nothing really elite level.
Cutting, pacing... The best '80s classics were all very tight and smooth-flowing, with hardly a frame wasted on fluff or boring filler scenes. And yes, some of today's action movies are too long, granted, and some of yesteryear's shorter action movies were fucking awesome, that doesn't mean shorter automatically means better though. Several of James Cameron's oldest movies are noticeably better in their extended version, Aliens and The Abyss in particular.
Well pointed, not wasting frames is one of the things that separate the trully talented directors from the hacks.
I haven't seen any attempts at looking at action movies from some kind of scientific point of view; do people like me love '80s action movies because that's when I was a teenager and I'm overly nostalgic and sentimental about them and their accompanying time era, or do I love them because they're genuinely great, awesome movies? Not sure!
Someone should screen some of the best '80s stuff to teens of today and get them to rate it all. Hopefully without them getting too hung up on lower quality special effects...
Nah, it's because there was a proper environment to produce these kind of films, (or even good movies after all) like the pgr Sigfried mentioned or the things you mentioned and a generation of great directors to produce them.
Think of the period between 1987 and 1990. Mctiernam was on fire doing, maybe the two best films of his carrier, the Pred@ator and Die Hard. On back to back years. Verhoeven did two of his best movies with Robocop in 1987 and Total Recall in 1990. Donner making Lethal Weapon in 1987 and it's sequence in 1990. You can even put the original sympathetic TMNT movie here and I am sure I am forgetting a lo of stuff stuff.
It was a truly great era. And today we have real life Star Wars on Hollywood, with Disney being the empire, the countless marvel film directors are the imperial destroyers, spraying bad movies all over Hollywood, commanded by that hack of Abrams, and it's awful movies and reboots being the symbol.
I would say that the decline of the action and blockbuster movies (or even overall decline) started about 20 years ago or so, between 1995 and 2000, and it stepped up in the last ten year. With many of these directors retiring or way out of their prime.
Oh and Dreed is really good, far better than that Stallone's stuff.