Bob Sheldon's parents provide no boundaries for their son, and consequently he does just about anything he wants without fear of punishment. As Randy tells Ponyboy, "They spoiled him rotten," and Bob took advantage of this freedom. He got drunk, stayed out late, and beat up greasers, and yet his parents did nothing to stop him and even blamed themselves.
"They thought it was their fault--that they'd failed him... They took all the blame and didn't do anything to him." (Chapter 7)
But, according to Randy, Bob actually wanted his parents to take more of an interest and that "He kept trying to make someone say 'No,' but his parents always gave in to him. Bob would probably have been greatly influenced by his parents if they had laid down the law once in a while, since "That was what he wanted." Instead, his parents' neglect only led him to greater acts of violence and self-destruction.