80's action movies may not have been well-written, but I'd say that the people making them were "smart". Good heroes, good villains, not relying on over-the-top CG used in ever-larger action scenes, a bigger emphasis on being exciting and fun, and not pandering to the young teen audience. It just seems like the people making action movies back then had a much better understanding of the genre than the people making the same kinds of movies today.
But, hey, that could just be nostalgia talking.