That said, even the trading of Soulbound loot in raids has its limits. Any Soulbound loot that drops in five-man content will remain untradeable. So, to address the issue, Blizzard has decided that the trading of Soulbound loot can only occur in raids. Raiders, on the other hand, accepted that it was the nature of large group play. The concern was primarily addressed for five-member parties. Mostly, they were worried that players who plugged into a group of players who knew each other might end up shafted by the other members in their party who could conspire to keep them from getting loot. However, players voiced concerns with the system. Hence the implementation of the system, which cut out the middle man and the wait. Prior to the addition of loot trading, the only way to fix this issue would be for players to contact Blizzard support and ask them to transfer the item to the proper player or party.
Before implementing loot trading, both parties were often require to jump through a series of hoops when the wrong member of a party accidentally ended up with loot intended for someone else. In fact, the functionality was added in Wrath of the Lich King to address to make things easier for both players and the game's support team. Loot trading was not a feature in Vanilla WoW.