Although Atticus lost the case, everyone, including Bob Ewell knows that Tom was truly innocent. The case made it clear that Bob Ewell was the one who beat up Mayella and just accused it on an innocent man. When Atticus is questioning Mayella, the fact that Bob is just a drunk man who does not take care of his children is revealed. These things ruin Bob’s pride (although I don’t think he has any good qualities that make hime worthy of it) and having everyone see that you are a lazy drunk would make anyone angry. The case made the Ewell family look like fools and Bob wants revenge for this. He confronts Atticus, spits on him and spreads rumours about him all to prove his manliness and save his face (although I don’t think this is helping hime, but instead is making him look worse). Also, because of the was he was likely brought up, Bob Ewell probably doesn't quite understand right from wrong. He was not raised in good, fair conditions like many other people in town so he does not quite understand the you can’t treat people that badly. All that he does is just a defensive act in order for the truth to not come out. He probably went after Jem and Scout instead of directly attempting to murder Atticus because he is too much of a coward. Atticus says, “I thought he got it all out of him the day he threatened me. Even if he hadn’t, I thought he’d come after me”
Although Atticus lost the case, everyone, including Bob Ewell knows that Tom was truly innocent. The case made it clear that Bob Ewell was the one who beat up Mayella and just accused it on an innocent man. When Atticus is questioning Mayella, the fact that Bob is just a drunk man who does not take care of his children is revealed. These things ruin Bob’s pride (although I don’t think he has any good qualities that make hime worthy of it) and having everyone see that you are a lazy drunk would make anyone angry. The case made the Ewell family look like fools and Bob wants revenge for this. He confronts Atticus, spits on him and spreads rumours about him all to prove his manliness and save his face (although I don’t think this is helping hime, but instead is making him look worse). Also, because of the was he was likely brought up, Bob Ewell probably doesn't quite understand right from wrong. He was not raised in good, fair conditions like many other people in town so he does not quite understand the you can’t treat people that badly. All that he does is just a defensive act in order for the truth to not come out. He probably went after Jem and Scout instead of directly attempting to murder Atticus because he is too much of a coward. Atticus says, “I thought he got it all out of him the day he threatened me. Even if he hadn’t, I thought he’d come after me”