There are a lot of ways to use the protocol amongst a limited, known, well-behaved group. As soon as you talk about it as an internet-scale service, controls are needed. Options and transparency are what makes it free not some magic of the protocol. People set up servers that get locked out of general delivery all the time.
Discussion
No shit. But spam filters are one thing, censorship quite another.
In fact, central banking/fiat currency types argue the same thing: if anyone could just spend their money however they liked, it’ll be used for terrorists! So we need to KYC you and know everything you do.
In an open protocol, things like spam filters will be built naturally as a response to spam. The problem with centralized platforms is this normal, necessary filtering gives way to something worse.