Why is Scout ashamed of her father?

At the beginning of Chapter 10, Scout laments about her father. She mentions that Atticus is old and feeble. Atticus is nearly fifty which is much older than her friends' parents at school. Atticus claims that he is too old to play tackle football with Jem, and Scout thinks that he doesn't do anything that is remotely interesting. Scout mentions that Atticus is nearly blind and needs to wear glasses. Atticus never partakes in any interesting, fun activities like the rest of the parents. The only thing that Atticus does is sit in the living room and read. Scout changes her perspective on her father after she witnesses Atticus shoot a rabid dog named Tim Johnson. Sheriff Tate gave Atticus the gun, and he killed the dog in one shot. The children are awestruck at their father's abilities. Miss Maudie tells Jem and Scout that Atticus' nickname was Ole' One-Shot Finch. Atticus never bragged about his marksmanship because he felt that his talent was God-given. Scout comes away with a new appreciation for her father following the event.