Time Traveling Hesitation
The reason people are so hesitant to Time Travel is that it’s a one-way trip. You sure can’t go out there letting the people of the past think it’s okay for them to step into our time. They’d bring a whole host of ugly things with them: disease, war, negativity. Nope, can’t have them tainting the world now when they did nothing to better it in their time, when they had the chance.
The reason I don’t Time Travel is because I don’t really care to see the past. If I were to go, I’d want to live the future. But I can’t do that, because they don’t want us in their world either.