Primarily training data. A lot of times it’s a hedge to show two things and let the user decide which fits their framing best

Most of the large models collected data from marketing speak, opinion posts, etc (the whole internet basically). I feel like it’s a common sales pitch I’ve heard many times over - now it’s just compounded with everyone having access to the same pattern generator clanker

Remember in Jurassic Park where the dinosaur DNA was extracted from mosquitoes trapped in amber? That wasn't necessarily the best DNA, just the easiest to extract. The best writing might be love letters or high school term papers or PRDs meant for internal distribution, and these never get put online to be fed into LLM training sets. Instead we have 20 years of StackOverflow and Reddit posts saying "it's not a bug, it's a feature" or "Die Hard isn't an action flick, it's a Christmas movie" with 10k upvotes and LLMs learned that's how you get the biggest reaction with the least amount of words. It's not a bug, it's a...you get the point