"communities are full of bullies who won't hesitate to call you or your mother names" - I think this is best put as "doing controversial things will attract trolls and haters".
"you must equally be a bully enough" - no, you just need to tune out the haters and continue to work towards your goal.
Lennart and the others underwent a ginormous effort to grow systemd from a borderline dangerous "I'm smarter than everyone else" toy project into something that's actually useful.
They did that despite the fact that the problem in question had been solved a couple times over (upstart was the last in a series of "improved" versions of SysVInit), and despite the fact that systemd adoption incurs a large switching cost of re-writing init scripts for all packages.
The art of leading a successful open source project is partly in tuning in to useful feedback and tuning out the haters who have nothing to contribute. Yes, the haters function based on ways that are similar to bullying. But while you can keep them off the mailing list, you can't ban them everywhere.
The more visible a community or an undertaking, the more visible it is for haters and bullies, and the more effort is lost on policing them or tuning them out. There's no way around it, other than educating the general population or staying a small, very technical in-group.