Note that the argument comes from the same group of people who pushed for mounting tmpfs on /run and /tmp.
My machine:
# df -h Filesystem Size Used Avail Use% Mounted on tmpfs 3.9G 4.5M 3.9G 1% /run tmpfs 3.9G 4.9M 3.9G 1% /tmp
10 megs of *RAM* consumed.
This was more about the cleanest way to have /tmp absolutely clean at start though I always thought .... Anything that sits in there for a while with little access will be paged out anyway...