I think privacy comes apart, when money is involved. I saw this happening on this forum when Ripple was introduced. People only had to link with their Facebook account to get some FREE Ripple in the beginning. This immediately compromised most of these people and their account was linked to their real identity.
After Ripple, we saw a host of Bounties and Coin drops and services where they require your social media accounts and some ICOs even implemented some AML requirements to participate.
Is the few dollars really worth your privacy? Your greed might cost you more, when people use this information to track you or even to link you to your main coin hoard.
Your observation is spot on and aside from what you see there, a whole lot of ICO will hide under whitelist to gather information about prospective applicants, while others that are bounty or airdrop defined will gladly gave their information away because of what will come out of it. But this post is surely not referring to them as they willingly gave them out either ignorantly or as a result of greed.
I am of the opinion of online privacy is not really applicable to me because I feel the sites I visits are mostly normal sites without anything to hide but this post is something more enlightening and would start implementing some of the recommendations there. Thanks Op.