I'm not sure the negative aspects are considered that bad, even by people who know about them. I really think techie sites just have an overrepresentation of online privacy advocates that steer conversations in that direction.
I think you'll have trouble not coming across that way because it almost inherently suggests your values (importance of the privacy of your data) are better than theirs (enjoying Facebook and that it is free).
This is the truth. The average person does not care about data mining. It's a non-issue for them. And no, it's not a matter of intelligence, or that they need to be educated on the matter. Leave them be. Ignorance is bliss - in a positive sense.
If you're going to teach others anything about the perils of the internet, focus on the truly serious things: how to avoid phishing scams targeting bank accounts, fake virus warnings, etc. Everything else sounds like tinfoil hat material because, for most people, that's pretty much what it is.
I've had a lot of people ask me if Facebook is listening in on the microphone on their phones - because they've been discussing something offline and then started seeing ads for it. Of course, maybe they've searched for it and then forgotten about it - but it's becoming a common topic of conversation.
Likewise, retargetted adverts are getting noticed more and more - people often tell me that they find it extremely creepy and annoying.
So there is a growing awareness out there ... it's just not reached a point where people want to take action yet.
I think you'll have trouble not coming across that way because it almost inherently suggests your values (importance of the privacy of your data) are better than theirs (enjoying Facebook and that it is free).