The original comment had to do with whether we should trust Cloudflare more than Facebook. If they as a company want to make editorial decisions, that's fine, but the reality is that also means they are not content agnostic. Interestingly enough, they provide services for known spammers and other shady internet operations.
As to whether 8chan 'caused' those abhorrent crimes, I couldn't say, any more than 'violent video games' caused them. I view such crimes as having a root cause of some form of mental illness, which does not (imo) relieve the doers of culpability.
The point is that they are demonstrably not exactly what they claim to be, and thus some level of distrust is warranted.