I didn't say it's copying anything. It's learning styles - all of them - in pre-training. Post-training is just about giving it the right defaults.

Doesn't change my point anyway - even if post-training, labs naturally want the LLM to come off as smart (well, except for Grok). Post-training is where they "untrained" em-dashes and such, due to complaints of users.

I'd heard an interesting theory that in training on customer chats there's a lot of interactions like this:

Agent: _wall of text_

User: yeah sounds great, do it

Which has the predictable outcome of biasing towards wall of text responses.