

Don’t offer it by default. Offer a feature. Then, separately entirely from the project, offer a block list or set of block lists. Have that extra step.
Nearly all software users, and yes especially self-hosting server admins, use default settings. By declaring yourself as the arbiter of all things bad and including it by default, you have changed your software from a neutral party, to one that is the arbiter of truth that requires effort to turn off, and that’s not something most are going to do.
Thus whatever you say becomes the majority opinion. This isn’t a new or surprising opinion btw, it’s the literal reason the DMCA has section 230 in the US, and all countries have something similar for platforms, scientific journals, and news organizations.
Apology accepted.