Atlassian do have products that cater to non-programmers as well, like Jira, HipChat, Confluence and some service desk application. I think Atlassian would naturally be worth more than GitHub, simply due to the larger potential user base.
I don't think we know what profits either company has, and without that information it's hard to know if the valuations are realistic.
Is that why Go is so popular in China? The "Our well-known customers" section on the Beego framework homepage (http://beego.me/) seems to list most of the largest Chinese internet companies, for instance.