TH, one can accept things and that is exactly what S is doing. It does not mean one isn't allowed to express feelings of anger, hurt, fear or anything else that is not "positive".
ALL of us would like to change things but sometimes in legal sense (which relates back to the financial sense) it's not possible as we don't write the laws. We are though required to follow them.
It would not matter if S got a lower paying job now as the precedent has been set for a LONG time with his current income. In the perfect world if he got a lower paying job closer to home it would take at least a year for a new precedent to be set to get a reduction. So during that time he would struggle even more and perhaps even lose his home.
You often come across as some of this stuff is no big deal. And I can even see from an outsiders POV why it might not seem all that bad. Living in a constant struggle that the courts have required you live under is draining. And the alternative of NOT having his daughter is not an option because he is a good dad. So he tolerates the draining but certainly can express frustration or sadness about it if that is what he is feeling.
When one has exhausted every legal avenue to change things there is nothing more to do other than wait for the court date to come. So he *does* accept it but it certainly does not mean he doesn't have a slew of emotions about it. And when one has negative emotions it is MUCH healthier to express them and not bottle them up until you just snap. And this is his outlet of expression.