It does, but it's an online forum, not an essential service, and easy to replace. On the other hand, being there with your name or nickname exposes you to harassment from those pissed at you for your decision.
I would say it's an acceptable evil given the circumstances.
As a side note: asking why after a mod action is almost universally pointless. Moderating is free work and a level of subjectivity is implied. I think not having the ability to argue is infuriating but understandable.
I will ask in good faith: given that those people started the whole project to have that space, but built it using federated technologies which allow others to run their places, what is exactly the basis for your complaint? As absurd as they might be, instances can decide their own moderation policies, whether you or I agree with them or not. Given the fundamentally distributed nature of this platform, there is no such thing as "having full control", and instead we can choose instances based on our preferences, so we are free to not subject ourselves to those policies, they are free to do, and both a free to use the platform in the way we use. The code is open, there are plenty of other instances. What exactly is the complaint here?