J.K. Rowlinged
When an author makes a cool book series and then decides to kill off all the good characters in the end just because they're too lazy to come up with a good ending.
I was excited for the final book, and it was just everyone dying for no reason. Ugh.
They killed off my favorite characters in the last book. What even was the point?
The author just wanted to finish the series fast and didn't care about anyone.