Tron is a film about a renegade programmer trapped in a system he helped to create. The film follows the standard trope from anti-technological films of the period, where the protagonist works against a system run on logic rather than ethics. I suspect that films like this were popular at the time due to the high anti-communist and hence anti-technocrat ideals prevalent in the American psyche.
As a bit of an aberration in the genre, Tron doesn't read as a cautionary tale, but as one of hope. A humanist hero conquers the anti-democratic system in which he is captured and returns freedom to the land.
It's an inspiring notion and a fitting image in an age where the most popular source for news in America is little more than a propaganda arm for one of the two dysfunctional political parties.