I have a theory that the laser in Tron, and Tron Legacy, can only re-materialize people from the digital world if there’s already organic material stored in it. Meaning that once Kevin and Sam were both on the Grid, it would only be possible to bring two people out again. It’s possible that Kevin knew this, and was prepared to stay behind all along. It would also mean that the Real World-Quorra is made out of Kevin’s organic material, moving her a step farther from just being his metaphorical, adopted daughter.
What’s really interesting about this theory is that it would mean that Clu’s plan for invading the Real World with a huge army was doomed to failure from the beginning. At most, he could get two people out. This lead me to imagine some different “what if Clu won” scenarios:
One creepy scenario would be that Clu would hide out the arcade basement and send out a lackey (presumably Rinzler) to kidnap people, who are then digitized to get more organic material to materialize more of his soldiers, slowly growing his army beneath the arcade. This would probably not work in the long run, since sooner or later someone would notice that people keep disappearing in the vicinity of Flynn’s Arcade, so Clu would probably never get all his thousands of soldiers out.
An alternative to this scenario would be that Clu pretends to be Flynn, and makes Flynn’s followers in the Flynn Lives movement his own computer-obsessed cult, which he grows into a huge organization, until he eventually digitizes them all in some big ceremony, replacing them with his soldiers. Again, pretty creepy.
Then there’s the comedy option where Clu and Rinzler try to pretend that they’re Flynn and Alan (kidnapping and digitizing the real Alan, of course), but are really bad at it. Especially the mindwiped, emotionless killer Rinzler, doing a really poor, Terminator-esque attempt at pretending to be human. Just imagine them having dinner with Lora, for example:
Clu: “Mmm, isn’t this food good, Ri… I mean, Alan?”
Rinzler: “Yes, Flynn. I am delighted to consume this organic matter to replenish my energy reserves.”
Clu (laughing nervously): “Oh, that Alan, what a kidder!”
Rinzler: “Yes. I enjoy saying unusual things to elicit an amused response from my fellow Users.”
Clu (sweating): “Humans, Alan, you mean humans.”