Here on TV Tropes, we tropers dedicate ourselves to cataloging recurrent patterns in fiction. Everyone knows that; it's the name of the game. Other sites deal with tropes, too, though none of them are as exhaustive as TV Tropes, which is perfectly normal. However, there's one site that takes it too far: it's supposed to be a free world-class encyclopedia, yet it's wasting time talking on and on about cliches in fiction. And that's our job! Isn't that a waste of bandwidth? Perhaps so, but the practice is a lot more common than non-tropers would think.
The truth of the matter is that Wikipedians do it for a variety of reasons—the trope may be common enough for scholarly interest, it may say something about psychology, it may be as much a real world phenomenon as an element used in fiction, or it may simply just be one of those many Silly Things Wikipedia does. On the other hand, it might also be because TV Tropes has fallen victim to scope creep, and the topic really is one that best fits in a general-interest encyclopedia. In any case, it's beneficial to TV Tropes; the more pages on tropes there are on Wikipedia, the more people will be led to our site.