When cloudflare accept provinding service to a customer they are linking their brand to whatever their customer do.. Should they not have the right to stop serving this customer if they are doing indirect damage to cloudflare business??
If someone get murdered because someone did something in a site hosted by cloudflare, sure cloudflare is not direct responsible for causing that murder but they do share the moral repercutions of it.. it sure get people asking, would that person not have being murded if cloudflare did not provide this site with the plataform they used to achieve this murder??
Having their brand linked to a site like this can be damaging to their brand\business\moral stance and they would be totally within their right to stop proving service for that..
as for the site/company/organization, cloudflare is not the only player around, if cloudflare stop providing service they can move somewhere else, they can even buy their own servers and host it themselves if no third-party hosting is willing to provide then services..