Right, the "free shit" part is when they profit from the data behind your back. THAT is the part that should be illegal.

But it should be a perfectly valid business model for me to pay someone to (for example) watch everything I do and everything my body does, and give me personalized health advice, as long as they keep my data under lock and key for only my and their proprietary analysis algorithm's "eyes" to ever see.

It's not the "tracking all your info" that is bad, it's that they legitimately believe that it's their info to do with as they please.