The media tabs which are displayed on the profile/groups page; have been re-factored in our coming release of rtMedia 3.0. Though the tab will remain there to indicate what kind of media is being listed on the page.
The quickest solution would be to hide the DOM element of the media tab with CSS; unless you would like to extend the widget and modify the code according to your need.
We have a plan to incorporate the media sorting in random order in our future releases of rtMedia 3.0. Till now you can check the progress of code at : rtMedia and test it if you would like. Though this is not the complete plugin and does not guarantee to work with full-fledged functionality. You may feed us with any comments/suggestions.