For example, I think mention of Creationism is perfectly appropriate for the article on [[Earth]]. Should it be the first mention? No.
I wouldn't oppose such an addition. The article already contains some information on mythology.
My main point is that Wikipedia says thinks like:
"The planet formed around 4.57 billion (4.57×10^9) years ago and shortly thereafter acquired its single natural satellite, the Moon."
Wikipedia could never say things like:
"The planet was created around 10.000 years ago along with the Moon and the rest of the universe."
While we can certainly describe the second view it is clearly something we'd have to attribute. The scientific facts can be stated in Wikipedia's own voice. This is a huge difference.
Regards, Haukur