What Azir spoke to him of proved the exact reason he could not simply tell most people that he was from the future. Because being from the future was an 'impossible' action, then anyone important would never believe it, and instead come up with alternate explanations.
The most he could do is show with his actions, information, and results, that it may be an option. If he brought it up first, it would be seen as him being too desperate to convince someone of the impossible.
However, given enough information, a smart, wise man will always reach the right answer, no matter how impossible it may be.
Lumi considered Azir's statement, and carefully replied. "You're right. There's no explanation I can give you that resolves the contradiction cleanly. Anything I say about where my information comes from will either sound like a fabrication or will raise questions I can't answer."
Azir watched him. "Because you do not know the answer?"
