I'd agree, but I'd like to envision a modular approach where multiple schemes can be maintained.

E.g. a menu containing...

"Scheme 1: / + swap + /tmp" "Scheme 2: / + swap + /tmp + /var" "Scheme 3: / + swap + /tmp + /var + /usr" "Scheme 4: / + swap + /tmp + /var + /usr + /home"

NOTE: See what I did there? There is no option for "/ ", explanation below.

I'm actually thinking that "not having a separate /tmp" is:

a. A security issue

/tmp is by-default out-of-the-box world-writable (perms 1777). Making this world-writable bucket part of "/" seems silly both for Desktops and Servers alike.

b. A nuisance

As "Da Rock" points out, ... recovering your system from a file-system-full-event when using "single-/" is just as difficult regardless of Desktop versus Server. Having "/tmp" alleviates the difficulty.

c. A performance issue

I'm surprised nobody has pointed out the physical performance limitations of rotating disks with respect to physical location of partitions on the spindle. Granted, seek times are light years beyond what they used to be, but allocating smaller "swap" and "tmp" partitions close to the center of the spindle is a performance-enhancing setup just as much as it is for protecting against file-system-full problems (security events included).

I'd argue that there should never be a single-"/" unless you are prepared to deal with a truly 100%-full filesystem problem (especially considering that Desktop users whom select the default-everything are often not skilled enough to deal with that situation). If someone truly wants a single "/" and nothing else, there's manual partitioning (which should prove pretty easy in the event that you're only creating one partition and nothing else).