Blocking is love
Block early and block often. That's how you create a healthy community. Communities that don't exclude anyone or anything eventually lose cohesion and fall apart. It's hard to maintain a sense of shared purpose if you tolerate members who have divergent or antagonistic goals.
There are an infinite number of possible goals. By choosing one goal you end up excluding an infinity of others. However there will always be people who spend their energy on changing the goal of the community rather than achieving the current goal. Unfortunately time spent fighting over goals or bikeshedding is time stolen from achieving the community's goal.
This doesn't mean that conformity or homophily are the only ways for a community to achieve its goal. However it does require us to accept that one of the challenges in trying to build a generative community is deciding which dimensions of diversity are helpful and which are unhelpful. Whilst you want a diverse range of perspectives you don't want perspectives that amount to "let's just shut down this project."
Instead you want constructive disagreements and the kind of conflict where everybody involved is dedicated to making progress rather than just winning the argument. This means having passionate fights about how you're going to achieve your goals whilst still agreeing on your goals. That unity of purpose is what allows the people who lost today's argument to come back tomorrow to make valuable contributions.
But that means having community members who accept that losing an argument doesn't meant they have to leave the community. At the same time they have to be able to accept that a particular argument is settled and move on to the next argument. This ability for members to disagree but remain committed to the community's goal is one of the hallmarks of a generative community.
Achieving this usually requires ejecting or blocking people who, to paraphrase Winston Churchill, can't change their minds and won't change the subject. Communities should think carefully about defining and enforcing their boundaries so that exclusion is an act of love not hate. Excluding a perspective or person should be a means of saying: "in this particular context we love the community's goal more than we love you but we still love you."