What The Fuck!!!

why not.... its the only way i can get new items because if you run out of room you cant pick up new ones...... that is stupid if they disaprove it, i mean you cant really do anything else and why would you sell good items if you have good items

Because if people didn't have mules, there would be less lag, and the value of items would be higher. Trading would be simpler, and people would be more encouraged to trade for items because they will have things they cannot use.