>Why can't I rip apart the UI of an app I use every day and rearrange it the way I want? And I mean, far more than toolbars and rearranging drop down menus. (BTW, remember those? Those were great).

IMO there's no reason you can't. Just yesterday I was playing with pavucontrol and thought "There needs to be a GNU Radio like view, where I can drop boxes which represent sound generating/taking programs/devices and draw connecting lines arbitrarily," then I thought why not the same thing for video treating even the contents of windows themselves as video sources too!

Table formats are easier to implement I guess...