It doesn't state in the CRB that it is a player resource IIRC nor that a reward is something that has to be very benificial, in fact the player can actively decide whether or not he finds the reward of doing an action worth the risk or not so obviously the obligation is indeed only taken on because of their choise. All of it as per the CRB.
Obligation is a powerful resource that may be spent and bargained with during the course of play. It gives the players an option beyond credits to obtain equipment or services they might otherwise be unable to acquire. - EotE Core Rulebook, page 309.