Respectfully, you have no idea how Windows 8's fast startup mode works. You also don't seem to know that Fast Startup is the default (so when you hit "shutdown" it actually hibernates most of the system's state).

Essentially in Windows 8 (out of the box) if you hit "Shutdown" then it logs the user out and then "hibernates" the kernel, the registry, services, drivers, and all other "system" level processes.

The computer is then ordered to power off (just like hibernate). When you turn the machine back on, a notice appears on the screen which reads "Resuming from Hibernation" and it loads the Hibernation file into active memory.

Fast Startup is essentially Hibernation without a logged in user.

Windows 8's boot times with Fast Startup enabled is very competitive to Windows 7's boot times using Hibernation (instead of "Shutdown"). It is also very comparable too as Windows 8 doesn't truly shutdown in the traditional sense.

If you boot Windows 8 without Fast Startup enabled then the boot times are very similar to Windows 7's boot times.

As I said, Windows 8 lies to you. It isn't faster, it is just pushing Hibernation in a new deceptive way in order to appear faster.