These aren't the most important movies in history of cinematography. Even I can see it.
But these movies have some kind of magic, that they attract successive generations of fans, fascinated, regardless the passage of time. This makes them so unusual. The characters, the stories... so, it's matter of taste, very personal. But I think, that this makes this movies so unusual. I think that many generations will discover the good old P1, if only because they will see AvP as the first or coming movie . Magic is still alive.
I'm not sure that it not attracted to the cinema a lot of people. But it made them interest enough that the myth could survive for so many years. And still is attractive.