Granted,
is awesome, but that's about the only thing easier for the casual user.
New linux users always make the mistake thinking command line is both necessary and too complicated.
Its neither.
Command line is rarely required, but allows anyone to copy paste commands from a website, email or whatever in to a terminal, regardless of what GUI you use, regardless of what language your OS is in, regardless (to some extend) of distribution or version. It even works when the GUI doesnt.
Now you can do just about anything through the GUI too (obviously including apt-get update), but explaining how to do it would take dozens of lines, possibly require screenshots, would be different for every different GUI and distribution, wouldnt apply to french or chinese installations etc. Try explaining over the phone or email to a computer neophyte how to remove AMD video driver. Perhaps then you will see who incredibly useful a command like
sudo apt-get remove fglrx
really is.
In linux, like in windows, you use the GUI if you are trying to discover things intuitively. If you want to remove AMD drivers through gui, just use the "additional driver" app or ubuntu software center, its intuitevely enough for anyone with basic computer skills to discover that. But you use the command line to be much faster if you know what you are doing, or if you are just implementing commands someone else wrote.
Both approaches make sense and have their uses, both approaches are available in linux. But in windows, you dont have that choice, most things require a GUI.