The funny thing actually is that repeating yourself is a really important communication skill. The model seems to have internalized that, but isn't yet quite at the level where it properly understands why/when to repeat.

It's probably related to GPT's more general sycophant inclinations. Acting like a doormat is apparently easier to teach than nuanced politeness -- much in the same way that repeating yourself ad nauseum is easier than intuiting specific points of emphasis.