I think what's happening here is selection bias. The people who proudly have no Meta accounts are replying to each other saying "me too". The hundreds of others who were reading did not reply.
I'm alluding to something a bit more interesting, I hope.
We don't have a way to test those hundreds of voices comprising the supposed silent majority. I'm saying that when/(BIG if) one does - via some hitherto undevised ingenious experiment which always yields truth - we find that no... in fact everyone is at best ambivalent, but mostly going along with what they think the majority view is.
I'm sure there's a name/concept for this in group dynamics.
Consensus mythology? (I'm just making that up)
A hallmark is that interrogating the group yields one answer, but each individual considered privately will give you a very different answer.
But it's not "group-think" I'm talking about, because that implies a more overt pressure. Rather it emerges in the absence of coordination amongst an implied majority when there exists a loud propaganda message designating some other group a minority.
I think this effect has important implications in the kind of 50:50 + swing elections we've seen over the past few years. For example, in Brexit, a mass of lethargic voters assumed "everyone will vote against" and didn't verify the reality by asking lots of diverse friends. It's not that people are trapped in actual bubbles so much as bubbles of their own mind based on assumptions about those around them.
Sorry, that's probably a long and clumsy way of saying something obvious.
in philosophy it is known as heterophenomenolgy hetero = same, phenomenology = experience