OK so this has happened to me a lot and at first I blew it off but now I am getting really ticked off.
If you are offering a pokemon for trade why is it so difficult to put the fact that the offered pokemon has a nickname in the trader notes? Some trainers like me do not want nicknamed pokemon and thus they are useless. At least to me.
From now on if I trade with anyone and I find out the pokemon they are trading me is nicknamed, and I was not told beforehand, I am cancelling the trade and leaving poor feedback.