We don't know that we don't need myth - It has been with us as long as time, and is deeply integrated in all our memespaces. I would argue that myth is a vital part of many people's world views because it brings them a joy they are unable to find any other way. I think that most believers of myths and the supernatural are incapable of living happily without their make believe faiths. This begs the question - should we as people even try to show them a worldview that is the opposite of what they can accept? I would suggest that caution be used when determining who is capable of handling a truth that may crush them psychologically. Enlightenment can come at a price that is too high, or it can be ignored entirely as some xtians here do.
Now, as for me - I'd pay top dollar for an ACME myth disposal attachment for my brain.
As far as myth is concerned, they all have a "moral to the story", a kernal of human nature within. But we don't need myth. Myth came from us. It is not the other way around. We should look at all the forces behind organized superstitions. Myth should be in folklore books not the basis for humanity's worldview.