Most of the time, yes. It has to be a really bad book for me to give up on it entirely. I also avoid skipping chapters (in non-fiction), even if I just want to hurry up and get to the later chapters.
The last book I gave up on completely was "Your Inner Economist." It had an interesting principle: how to negoiate all sorts of situations (involving money or not) based on economic principals of what people are willing or not willing to do. However, the writing was about what you would expect from an economist who had no real training as a writer. Luckily I only paid a $1 for it at Books-a-Million.
I just finished reading "The Vanishing American Jew" by Alan Dershowitz–but only because I was tenacious. The information in it was good and interesting, but it needed to be shorter. Out of a little over 300 pages of text (not counting endnotes), I think 50 pages could have been cut. In places he took too long to get to the point, and in other places he repeated himself.
It makes me appreciate the necessity of keeping the books I'm writing (https://keripeardon.wordpress.com) trimmed down. I'm naturally wordy and when I start to write, it takes me a page or two to get warmed up; all the more reason to go back afterwards and trim.
Keri M. Peardon 