That doesn't have anything to do with the show's dialogue, it just means the sub group you downloaded from had a particularly creative translator
"lol natural dialogue" is not the sole factor of good writing anyway. Good writing is a combination of "good plot/story" and "good characters and character interactions"...or that's what I consider good writing anyway
now /a/, on the other hand, decides whether a show's writing is good or bad as follows simply by deciding whether or not they like the show. If they like the show (or everyone else hates it and they feel like trolling), it has great writing, great characters, and great dialogue. If they hate the show (or it's popular here and they feel like trolling), it has terrible writing, terrible characters, and terrible dialogue. If they don't really feel too strongly one way or another, they call it decent and don't post about it.