Why doesn't ClockWorkMod wipe of /data delete /data/media folder? I think this might be a simple question but this been bugging me for long, 

Why is that when i do a ClockWorkMod wipe of /data, the /data/media folder stays intact. @beeshyams pointed out that it is to avoid wiping out any clockworkmod backups. If that is the case, only /data/media/clockworkmod/ folder will stay untouched if backups exists or not. But rather the whole /data/media/ folder is kept safe from harms way. A better explanation will be appreciated.
Please note the following are assumptions based on my Linux knowledge. So I cannot 100% back them, especially cannot tell if any/all recoveries work this way.

First, some raw facts:


as already pointed out, /data/media is a symlink to the SD card
resulting of that, the data behind it reside on a different partition
that other partition is usually not included with the wipe/factory-reset, which normally covers only /data and /cache


So now to the wipe itself. "Emptying" the /data partition could be done in different ways:


"formatting" the partition: wouldn't touch the data behind that symlink
performing something like rm -rf /data/*: would remove the symlink, but leave the data behind it untouched
walking the entire /data/* file by file, directory by directory, removing each entry (no idea why one would do that). In that case, unless the process follows symlinks, again only the symlink would be gone but the content behind it left untouched


So once more: As the data-in-question does not physically reside on the /data partition, it should even be expected to stay.