.. are those considered "good" ? github is meh at best considering it's 13yo and the billions of dollars poured into it, and wordpress, I don't think anyone can reasonably say that it's a sane software. They are both good arguments against dynamic typing imho (especially the latter).
If what you're saying is true and those software are mediocre at best, this implies that software quality and success have no correlation. Or perhaps that software quality is not at all what the users of this site tend to think.
But the least successful art is in every measure bad. I mean for example the movies that score 1.0-2.0 in imdb. But yeah, perhaps the comic book movies are not unlike Wordpress.