I don't think your distinction (or judgment) here changes OP's point. It might be a solitary, textual endeavor, but the question remains: why are women less prone to dedicate time to this sort of stuff.
The answer OP poised was that Wikipedia and Open Source require text based interactions with others in the community - beyond the actual exercise of writing wikipedia pages and writing code. Thats the difference here, not that women don't like reading or writing.