Having the ability to trade almost always leads to duplication glitches. So limiting it to once a year to giving a gift to your friends once is not a bad idea in loo of the season. Also nobody said random. Say your buddy wants the vex mythoclast and you have four. He can trade you something of equal value in the form of giving an item as a gift to you in order to receive. Having full on trading in Destiny is something we aren't ready for. Why not test the waters and learn to be a little nicer once in a while...