The very fact you had to use Google to learn how to shutdown your PC is emblematic of this.
I agree about this one single particular point. But that isn't "emblematic", it is a single point that is a very separate issue than any of the rest.
Besides, it's not like shutdown has ever been obvious. In Windows 3.1, you had to go to Program Manager, then the File menu and then you had the option to exit Windows. In Windows 95/98/Me/XP, you had to go to Start to shutdown... how does that make sense? In Vista and 7, you first have to go to the orb with the Windows logo. Vista was even more confusing because it gave you a red button with a circle/line symbol for shutdown (whereas 7 used the words "Shut Down").