I can't imagine who is saying that time travel is impossible. Certainly no one in this discussion. I have, in fact, disputed that comment several times.Concerning the time travel aspect of this debate, how can you, personally, prove that time travel will never exist? How about in 1000 years? Do you know how advanced science and technology will be by then? Scientists already state that there is nothing in Physics preventing time travel, meaning that it isn't obsurd. It is only a matter of time before someone figures it out. This means that time travelers from all over the universe could be visiting us. This is what makes the Titor story believable. No hoaxer has developed a story so intricately as Titor has. The hoaxers stop after a few days because of all the questions. If Titor is a hoax, it was done by some very smart people. Yes. People. He definitely was a team.
IMHO.
As for the "Titor" narrative, there is nothing intricate about it. As with all trolls, he vanished into the ether after stirring people up. Yes, "he" stuck around for a few weeks but only responded about once a week and only to a select few posts. The only thing creative was his solution to avoid answering questions with specific"future" information which incidentally allowed"him" to continue the fantasy without providing a shred of proof.
In conclusion; is physical time travel possible? I don't know. Did "John Titor" aka timetravellr, establish himself as a legitimate time traveler? Not even close.