I believe that its more a case of showing respect to the other player. There is no need to talk about the weather, how pretty your lights look, the price of a beer at newark station. Its simply a courtesy to the other human player controlling the hostile character, to not simply open fire on them.
Aside from that, as the others here have pointed out, it is in fact a server rule.
I try to have fun with it. eg:
Navy: Oi Rogue, yer filthy maggot infested pile of cat spew! you have 2 choices, a 3 by 3 meter cell, or suck vacuume!
Rogue: oh really? Then come and get me! Just you try it, if you have the guts!
