Because it doesn't use cloudflare duh.?

From their response headers, it seems like the request is coming from NGINX directly. How do they defend themselves against DOS attacks?

	▲	sunbum 38 minutes ago \| parent [-]
		Big server. And if it goes down it goes down? Who cares, it's hackernews.

I have a handful of sites DNS/NS through Cloudflare, with their certificates, and they are working OK.