We write stories and in doing so create people. As we have the power of creation then we also have the opposite.
I began reading Patricia Cornwell's Scarpetta novels a number of years ago and find them compelling, tense and satisfying. You really feel that you know the lead character, Kay Scarpetta, so it is hardly surprising when there is the possibility that the character is going to be written out, that the fans react.
I had a similar reaction just last Sunday when discussing my writing with a friend. After the obligatory back handed compliment I was implored not to stop writing Steele novels. This was in response to the information that I was beginning a historical novel, The Magic Show.
When I began writing I envisaged 10 novels but at that time they were all going to be Steele, however, I have already changed that plan and written a futuristic, dystopian novel. Currently, I'm running at 9 Steele novels and Cessation, the dystopian story. The historical story should be completed by the summer if all goes according to plan.
Returning to the writing out of a character, it is undoubtedly, for the creator, as traumatic a step to take as it is for the readers. I had planned to finish the Steele novels after 10 but it all rather depends upon issues that arise in the meantime. Many writers use their stories for social commentary and in that I'm no different. Steele has on more than one occasion provided me the vehicle by which I have expressed opinions on a range of subjects. These have included, people trafficking, USA colonisation and misuse of the CIA, inequality of the class system and government misinformation. They haven't all been 60k+ politically motivated rants, I have my readers to entertain, but there are social comments being made. So for now the ending of Patrick Steele is not in my thoughts.
With regards to Patricia Cornwell ending the Scarpetta stories, she will do what she, as a writer, needs to do.