Reading the end first saves a lot of time. I hate it when main characters are wasted or when the characters journey goes nowhere. That goes especially for long running TV shows that I haven't seen yet and am about to watch. I always check first if it's worth investing precious time on it.
How can you evaluate the character's journey without reading the whole story?
If the plot for example is "character fights to survive" and eventually dies, there's no point for me reading it.
If Lord of the Rings ended with Frodo failing and Sauron winning, I'd thrown the book away.