I think "naysayers" are useful. Having people offer more "everyday" explanations can sometimes help shed light on these mysteries. Personally, I appreciate it when people don't just say, "yes, you've seen aliens" when I describe a light in the sky I can't explain. I think we've all had things we've wanted to believe, sometimes to the point of self-deception (she loves me, I don't look fat in these jeans, I'm not balding). Isn't it better to have people who bring ideas that help us think all sides of the issue through? Maybe she loves you. Maybe there are aliens wisking you away in the middle of the night for testing- who knows!? Maybe you aren't losing your hair. I'm sure you did see those things- but that doesn't mean I believe ghosts are necessarily behind it.
Wanting to believe something to the point that you can't really bear to hear another side of it- doesn't that sound a bit familiar? Diversity is good.