Or, more likely, it's that concise code requires a much deeper, wholistic, understanding that these models just are capable of yet.

Same with a junior dev. They don't write long form spaghetti because they're trying to write more LOC. They do it because not doing it is hard, literally above their pay grade.

I use LLM every day, but they're still completely awful at architecture. I don't think this clear lack of ability is some conspiracy.