I see it incase they receive a chargeback. Most credit card companies only dispute charges back 90 days. By holding the name for 60 this gives them a month to sweat it out incase of a chargeback. Otherwise someone will register tons of names and then transfer them away and GD is out the funds. I do not see why most people transfer their names out just because of this rule. Like Daddy said above, it's an ICANN rule. I am sure Moniker, being ICANN accredited, will abide by this rule sometime in the future.
Big whoop. If you are selling a name, like mentioned above, credit a free godaddy account and transfer the name to it.