The hits on “Main Page” will be people just going to the site. The hits on “wiki” will not (I would guess) come from a society-wide fascination with editable websites, but because people have typed “wiki” into a search engine. I suspect a lot of the sex-related hits will be disappointed porn searchers.
The question is what “popular” actually usefully means. Raw page hits demonstrably isn’t quite it. “Pages with most hits gone to by people looking for information” (whether starting from Wikipedia, a search engine or a link) is closer to what we’re after, but there’s the question of quantifying intent. When we ask what’s “popular,” what’s the question we’re actually asking?
(At least our charts are harder to rig than Conservapedia’s.)