The passive attacks on dTPMs in question require physical access, and opening the computer (and can be defeated with software). That is a pretty unlikely event for most users' computers. Active attacks (which can also be defeated with software) are more interesting because those are more likely, since the user doesn't have to cooperate with the attacker in those attacks.

That's how console jailbreak mods have worked in the past.

The important keyword is authenticated though. If it's not authenticated you can corrupt it.

They're doing all this to prevent... console jailbreaks? I would have expected some kind of national security use case.

National security information is usually in a better protected environment than a game console or your laptop.