OT: Relays

Going through some info to order some phoenix contact relays i notice that one feature they tout heavily on many relay / base models is " Seperation of coil and contact wiring".

What is this supposed to prevent or help? Seems to be that it makes cabinet wiring easier but how?

Could not find a lot on the theory of it so i thought i would ask here. Just noticed that a lot of there relays have that.

Here is a example link http://www.alliedelec.com/Images/Products/Datasheets/BM/PHOENIX_CONTACT/909-0060.PDF

9th feature listed on the sheet.

Coil wiring is on one side of DIN rail, contacts on other side. Makes it easier to route wiring. Low voltage control on one side, output on other.