They blocked Nazis after some attack or something like that. The founder wrote an emotional letter back then, acknowledging how bad is this and how he hates becoming the internet police.
> The tipping point for us making this decision was that the team behind Daily Stormer made the claim that we were secretly supporters of their ideology. [0]
That's in a blog post which is a follow up to a leaked memo. [1]
[0] https://blog.cloudflare.com/why-we-terminated-daily-stormer/
[1] https://gizmodo.com/cloudflare-ceo-on-terminating-service-to...
[0] https://blog.cloudflare.com/terminating-service-for-8chan/
Yes, because he is a troll... he got exactly the response he wanted, infamy and people still talking about it years later.
And the proper response from CloudFlare should have been: No we don't, but since we're ethical (unlike these assholes), we'll still provide them service.
Literally no one believed then, or believes now, that CF are crypto-Nazis. But we all know they don't actually have any kind of moral or ethical virtue, and will fold for a common troll. Oops.