I would imagine it's because there are not a lot of gui tools to use git. Especially on the mac and most of them are not "full featured." I really like gitx but it doesn't do a lot of the more advanced stuff.
Yeah gitx really bother me. The whole point of git is its amazing power. As much as a nicely designed OS X app makes me feel good, I'm not about to throw out the power of something like gitk and the speed of the command line for basic tasks in exchange for a watered down interface.
Even though gitk commits some of the most heinous UI sins on OS X—such as remembering large windows even after switching monitors so that you end up with a box that can not be resized without editing ~/.gitk—it's still head and shoulders above all the native OS X apps I've tried.
If a commercial product is good, I'm all for seeing it garner votes on HN.
