shutdown on BSD and Linux

[Rahul Siddharthan <rsidd@xxxxxxxxx>]

I've long had a question on the shutdown process.  Linux systems run a
separate shutdown script for every process that was started at boot,
and can take a minute or two to shutdown.  FreeBSD and Dragonfly, as
far as I can tell, just kill all processes, flush buffers, unmount
filesystems and shutdown/poweroff, which takes about 5 seconds.

So what's up?  Is BSD-style shutdown dangerous, or are the Linux
people stupid?

The question came to my mind again when I saw Ubuntu's specification
for shutdown in their future versions:
   https://wiki.ubuntu.com/Teardown

Basically, it says the majority of init scripts needn't be called at
shutdown because the processes can just be sent signals and trusted to
do the right thing.  However, some controlled shutdowns *do* need to
be done.  Why can the BSDs get away with not doing these controlled
shutdowns?

BTW - the poweroff on my laptop, with Dragonfly and FreeBSD (last I
checked), is also accompanied by a rather alarming and short-lived
whine, as if a spinning disk or fan was suddenly stopped.  I don't get
this sound with linux or windows.

Rahul