^^That is more believable.The actual problem is in the way they entered the digital world.
Imagine a human vanishing into something like a 'motherboard' with his entire body!thats ridiculous.May be they should have shown it in a way similar to that in the matrix.
Well, by the definition, a Sci-Fi is "a literary work based on the imagination and not necessarily on fact".
And then comes the science of
teleportation.
According to the theory, teleportation is done, by dematerializing the original body, transmitting as data during the journey, and then reconstructing at the receiving end.
In fact, the original Tron (1982) actually shows this process, of the body getting dematerialized. So, the story makes sense to me, atleast from a Sci-Fi point of view.
Also, it doesn't happen much, when we get to see, the sequel getting higher votes then the classic. But, it was probably because, the concept of digital world was maybe too over-the-top at that time.