Many hold the opinion that if they ignore it maybe it won't hurt them but i have always thought that if people are really interested in finding out what is true they would at least want to look into it and see if there is anything to it.
Ohhh and don't forget that there are those who claim that ufo's contain satan and his evil angels...even thought that seems to be just a fear of the unknown and not supported by anything other then opinion. But I think the whole subject is pretty interesting and deserves a very serious look.