I think you really need to read some history. If there's any old-world parallel for space travel, it's the ocean. The ocean was downright deadly and could snap a ship in half on a whim. There was practically no job more dangerous than sailing, but able-bodied people LEAPED at the chance to go out onto the high seas, whether it be for fame, fortune, or just some healthy adventure. I think you greatly underestimate the ambition of humans. And really, if we only did things after we were 100% sure it was safe, we wouldn't even know how to use fire.