Maybe they think "you don't have to use FB"... By that logic "you didn't have to use AT&T or the internet at all" either.
And then there's also the thing that, arguably, Google and FB give those people something in return which they might consider worthwhile for just data. I'd question that the majority of the user population is aware of the implications of handing over data about themselves and specifically other people, who may or may not be okay with that.
All the more reason to keep an eye on the people who control the page that so many people view their news from these days.
Given that the mass media is in direct competition with FB, I wonder why they haven't destroyed FB already.
All things considered, Facebook presents a similar level of risk, especially if nation states use it as a digital weapon as we've seen recently.
When the state tells you its on, its at least to your face.