I m wondering why no one is using a proper case for 4x GPU mining rigs.

The cons I can see are (in my perceived order of importance):
-can only handle 4x GPUs
-adds to the cost (about 50$)
-lowers air flow
-can only be used with blower style cooler GPUs (open air coolers won't work because the cards are too close to each other)


Pros:

-it seems a bit more compact that racks
-noise levels would seem lower
-lower risk of short circuit/things falling appart if someone (dog/cat/kid) bumps in the computer/in case of earthquake
-it would be easier to repurpose the machine to something else should GPU mining become unprofitable
-it would seem easier to stack up machines for a mid sized farm (about 10 machines )

I m currently mining with my existing computer which I upgraded to 4x RX480 reference with blower fans and I m very happy with it.
I have kids running around and live in Japan where earthquakes are common so I would never use racks.

I seem to be the exception. Why is everyone using racks?