We can maximize user freedom by having developers put code into a commons, reject the freedom-to-restrict-users, and deny other developers the ability to enclose that commons in those sort of restrictions (ala copyleft).
This has an even more broadly applicable analogy, Popper's "tolerating intolerance" and related paradoxes.[0]
Another way of looking at this is through the frame of positive and negative freedoms[1][2] (often described as "freedom to" vs. "freedom from"). It is often not possible to maximize both. For example, when the goal is maximizing human freedoms for the most people, it is not unreasonable to disallow making any people un-free, which includes denying people the freedom to sell themselves into indentured servitude.
[0] https://plato.stanford.edu/entries/toleration/#ConTolPar
Why can’t or shouldn’t the “Spirit of Open Source” be able to include exactly the things that you complain about? I would love to hear your grounding for your position :)