Except it does not though. Making a feature opt-in is literally the most friendly and permissive action that can be taken in such matters.
Btw Lemmy v1.0 gives Lemmy.ml sole veto power in suggesting community names to new instance installations. But it too is not so much hard-coded as opt-out.
Both platforms are rather opinionated, but the amount of disinformation targeted against PieFed is significantly higher.