GitHub is great but there is a group of people, many of whom are on HN, who prefer OSS to be on non-proprietary systems. Personally I think you should just use whatever tool works best but not everyone agrees.

Git is a distributed system but almost every single time GitHub goes down you get people complaining about OSS and others using / relying on GitHub but honestly you really don't have to at all. Git was designed so you wouldn't need to.

So yeah hating on GitHub can be a bit popular on HN.