They have no way to make an informed choice, or even to make a choice, and there is no media who speaks out for them. There is no wallet for them to vote from, and no competition to choose from.
Instead the whole move is designed to prevent them from making choices, in the future, choices that are contrary to Facebook's market domination.
I see your point, but most safety regulation could be criticized the same way. We as a society won't allow you to buy or sell a house that doesn't meet building codes, meat that doesn't pass inspection, etc.
This is a restriction on your freedom and could be viewed as paternalistic, but it also prevents poor, desperate people from getting sick living in asbestos houses.
Is Facebook-controlled internet like an asbestos house? Arguably.
It's so easy to make choices for others when you already have what they don't.