One of the things I hate is when a supposedly likeable character behaves like a tantruming 2 year old, and the author wants us to approve.
There was a book I read years ago, in which the heroine stumbles upon a conspiracy where she works, and by the end of Chapter One, she has become the victim of a bungled murder attempt (hit and run accident), and she is lying comatose in the hospital. She is trying to communicate psychically, but in the meantime: her soon to be ex-husband wants to pull the plug, her doctor wants to pull the plug, and the killer has managed to also get himself admitted to the hospital because he wants to, well, yes, pull the plug. Enter her brother, a man so desperate to save his sister that he constantly shows up, screams and yells, grabs at doctors and nurses, attempts to snatch at charts and medication only to be asked to leave. Asked to leave? Heck, no! They should have committed him.
Now, I know why this writer did it. From Chapter One, the supposed heroine is in a coma. She never speaks to anyone, you never get to know her as someone that you want to live, and since everyone else was at best, indifferent to her, or at worst, actively trying to kill her, the author had to generate someone who cared. But the brother was such a pill!
I stopped reading Kathy Reichs for a few years because of a similar situation. In one of her books, a crime scene had been rigged to look like a Santeria altar, and a local politician was trying to use the crime scene to support his conservative agenda. So politician would show up, Tempe would see red and cause a major scene, complete with the press documenting it. She was warned that she was in danger of losing her job, and yet over and over again, she was screaming and shoving at him. I know that Kathy Reichs was trying to establish that the politician was a bad guy, but I ended up feeling sorry for him, and I wanted Tempe to lose her job in that she might finally admit she finally had a problem.