The very first time Bob went to jail, he used his one phone call to contact his mother. He believed that his mother owed him, considering that it was partly her fault that he'd ended up in this predicament, giving him unsavoury ideas. However, Mother had coldly refused to provide him any bail money, or a lawyer, or even the tiniest bit of sympathy.
"You have brought shame on this family, Robert. You're on your own, now."
Bob had to resist the urge to rip the phone off the wall. Mother was such a hypocrite: she'd done plenty of shameful acts in her career, as had Father (Father's questionable dealings with certain mortuaries throughout the state came to mind).
The worst shame of all was feeling ashamed of yourself. Bob did have that feeling more than he would ever admit, but he repressed it the best he could. He knew he shouldn't be having murderous thoughts about a child who had only wanted to help his hero, and that his perpetual pursuits of that little brat were wastes of Bob's vast talents and potential. It wasn't as though Bob had not made an effort to improve the world, through the creation of good, non-patronizing programming for children, or through replacing the corrupt Mayor Quimby, or through becoming a Christian, or becoming the beloved mayor of Salsiccia, or getting married. When Bob was in a more lucid, self-aware mood, he realized that it was his own mistakes that had ruined things for him, almost as much as the Simpsons had ruined him. It was for this reason that Bob didn't like getting too self-reflective.
Bob hated himself, more than anyone else who had wronged him. He regretted those chances he'd lost at being a better brother, a better son, a better husband, a better father, a better man. Sometimes he wished it were possible to die of shame. At least this cycle of misery would end at last.