I can't speak for everyone, but I can explain why Tron was such a big deal for me as a kid. Up until then every single sci-fi movie was set in the distant future or a galaxy far far away. I was 6 or 7 when my Dad brought home our first personal home computer from Radio Shack. It was a TRS-80 model III made by that giant in the computer world, Tandy. A magnificent piece of technology that was able to run cassettes AND floppy discs. It was the dawn of a new day for me and my young mind was still trying to absorb the reality of it all. It was also the catalyst for my love for video games. More likely than not I imagine my father bought the game just so my brother and I would show some interest in this weird monochrome box he had brought home. Well it worked better than he had hoped. I spent hours playing that terrible game. The game was suppose to be training wheels until I understood that the computer was really for making spreadsheets on green and white striped paper. When I saw Tron it wasn't about alien technology, this was about something I had in my own home. Not only that but the hero in the movie had to survive by playing video games. It vindicated my new found passion. Here my father was wasting his time doing data entry while I was training for the necessary life skills needed if a laser shoots me and I get trapped in a computer. It gave new exciting life to my Trash 80 and all of the sudden I got a glimpse of a future that I one day I would live in.

http://www.radioshackcatalogs.com/catalogs_extra/1982_rsc-07/

If you want a blast to the past