Lucas Blackstone
Explorer
The player's aren't monsters so intimidate won't work against them for purposes of giving up. It's included on the sheet because not everyone the orc interacts with is going to be the PC's. For instances include any NPC's that are with the PC's, minions of the PC's (bet your ass it's gonna be in a splatbook eventually), or if the PC is being interrogated and fails a Will check, they blurt out a secret, etc.
Where does it say players can't be forced to surrender via the intimidation skill? If you can be mind controlled to attack friends I don't see why you can't be forced to surrender.