I don't have a strong position on the broader issue, but I feel like this argument ignores some context. It's one thing to sign up for your local car wash's loyal program and have them do some lightweight customer research on the data. It's quite another for to input your demographic info and interests into a social networking site and have it be analyzed by some of the most sophisticated data analytics in history. The potential downside/cost to the user is orders of magnitude larger. I think it's a stretch to say the user is giving informed consent to (for example) have their manual photo tagging be used to train a model so that a computer can identify their friend's faces automatically. The average user has no idea such a thing is even possible.