The Giant KoreanThe reason why we never meet time travelers is because our civilization ends before the technology can come to fruition.
lurch (he/him)nah, the reason is: when you travel back in time, our gakaxy, solar system and planet are in different absolute universal positions. so you end up alone in deep space and by the time the planet reaches your position the time you traveled back has passed, making it absolutely useless and life threatening.
Have you noticed the flashing light in the sky? It started last year. It gets a little brighter every night. I only used to notice it when I was out of town, but now I can see it in the city. It blinks pretty quickly, probably twice a second. Some blinks are longer than others. If you watch long enough, it repeats. Short. Short. Short. Long. Long. Long. Short. Short. Short.