alt Hacker NewsArticle seems to answer the question: because generated text has the competing objective of information density and supporting reasoning chains.
But I also wonder why AI loves to add slogans, catch phrases, and witty sentence fragments. It’s grating and a dead giveaway of slop.
Because people love to add slogans, catch phrases and witty sentence fragments, and AI was trained to mimic people. AI has shone a spotlight on it, and because AI isn’t perfect, it tends to overuse and use it where it shouldn’t. But go read news articles, blogs and corporate press releases from before the AI boom and take notice how often AI “tells” also show up there. The internet made hot take mic drop sentence fragments, “witty” turns of phrase and clickbait “it’s not foo, it’s bar” cliches a core part of its lexicon. It really shouldn’t be surprising that it shows up in AI too.