But spam emails are delivered to my inbox along with all my real mail, cluttering it up. Wikipedia entries are not pushed to my attention and do not clutter my experience. I don't experience them at all.
Yeah, and some people want to use wikipedia just because you want to use your emails. Some people want to read stories about people they care about, not some random doctorate that added themselves to wikipedia for the sake of self-promotion.
It's about valuing the user experience first and foremost.