Nardpuncher
Rear Admiral
Nope.
Well... never mind, I was, for part of it. I couldn't see much, though, if you follow me...
But the key 1955-'85 difference is the cultural tumultuousness of the sixties and seventies, which were far more impactful than anything that happened in the nineties or the aughts. We've even started to forget about 9/11, in everyday life at least (or else 2012 would never have been greenlit), but no one in the 80s could ever forget about Vietnam, or the Cold War.
In the 80s, people were going to Star Trek and 007 movies, watching TV, starting to use cell phones and computers and were dealing with hostile Middle Eastern governments and terrorists. In 2015... we'll likely still be doing all of that.
You're right in that there just isn't enough of a difference. Music is different and fashion to a degree, but it's the different mind set that helped make the humor in the original movie.
By the way, I saw the original movie in the theater at age 12.
All I want is Marty's shoes from the future (don't really need power laces) I heard Nike made a limied amount a couple of years ago.
Pepsi should come out with Pepsi Perfect in those bottles for 2015 too!