Author here. Similar reply to one I did below, but a significant amount of developers I work with in enterprise or corporate contexts don’t have this similar situation. Cloud9 can be fairly liberating for them short term, especially while learning the ropes of AWS.
The majority of HN readership I’d encourage to continue using their own tooling, you’ve got fast internet, unrestricted access and powerful equipment.
That all said, I default to Cloud9 these days just so I can bounce around machines and have a consistent dev environment when I need it. A lot of my daily job is meeting teams where they are and helping them be productive fast as possible so I need to stay semi-fluent in most operating systems.