People don't realize that space is huge. Seriously, freaking, massively huge. So huge it makes your head spin, and phrases like "speck of dust" and "grain of sand" don't even begin to describe how insignificantly tiny humans are in proportion to the rest of it.
So it strikes me as funny that there's even any controversy about the whole thing. There is life on other planets. Period. It would be impossible for there not to be. It's just incredibly spaced-apart. The other planets in our solar system probably do have, or once had, life on them. The nearest intelligent life is probably so far away that no one on this planet will ever hear, see or know of them, ever, and vice-versa. People's perceptions about space have been too distorted by TV and movies.