The most charitable guess I can make is that they use it to improve their driver assist, lane keeping, pacing, and that sort of thing.

location and g force and direction when the automated system shuts off and returns control to the driver, that sort of thing. I don't agree with it, but that would be my guess.

I own a Subaru that does this, so I'm not happy about it, but what can I do?

That's rhetorical.