I understand your point, I really do. But I disagree.They do share the money they take in by providing the service to their users without charge. That does not justify tracking people without their consent, but your framing is incorrect.
So am I. I have no problem if people choose to be tracked, but it should be an informed choice.
First, I don't think the money they make by milking our personal data is on par with what the service they provide is worth.
Second, following your logic, if (and that's a big if) they actually "share[d] the money they take in by providing the service to their users without charge", why adding intrusive ads on top of collecting our personal data? Why taking the ownership of some stuffs (if I'm not mistaken, the photos you upload on Facebook can be used w/o copyright infringement by Facebook as they please). If your logic were true, milking our personal data should be enough, no?