I agree with most of the posters here who feel that "YOU", the individual" change, not the movies. And that is a really good thing, if you think about it.
Could you imagine being the same person you were 20-25 years ago. I am 42 and am in no way shape(physical wreck
or form(mentally) am I the same person.
And if you have lived as long as I have, and you still are the same person, I am sorry, but that is pretty PATHETIC.
And I really mean that.
I heard an interview with Brian Cranston on Howard Stern about 6-7 months ago. He was back at his H School reunion, or something of that ilk. And that very statement was posed to him by a classmate he had not seen in 25 years, or longer. And his response was "Well, of course I've changed. Haven't you?!" He felt it was a pretty dumb statement, and I have too agree.
There was A LOT more to the answer than just that, but that pretty much sums it up.
So, NO, movies do not get better, or worse with age/time. Your sensibilities change. You as a person GROW UP. And different experiences make you 1000 X different than what you were 20 yrs ago or longer.
That IS the answer.