Intention of the post is to show various ways in which we can use git and they are allowed uses too. For e.g. MySQL uses GNU GPL too, you can use it in your poject and use it for any purpose.
i personally always get a small giddy thrill when i see such a wide spectrum of applications from a simple underlying concept... just like these. and each application alone is cool! DB, wiki, dropbox-clone... very, very cool stuff when considering the implications of integration on /that/ level.
but apparently this isn't a universal sentiment, given some of the comments on this thread (that i am genuinely surprised at, given what i would think is the typical "curious/hacker" mentality of the crowd here).