Looking at it from a different perspective: creating content requires lot of work, while consuming content requires little to no effort. Hence, looking from this perspective, it's natural that the majority of us are content consumers and not content producers.
It's timing too. I would've commented something along the same lines as you but of course by the time I got to reading the comments on this post it already had 148 comments, at least one of which covered what I would've contributed. The same goes for Wikipedia - everything I would be confident enough to write about is pretty well covered.
