Personally, when I find that a book I am reading is not to my liking - for whatever reason - I stop reading it. Whether it's a book I've chosen myself or a book club book or one recommended to me, I stop reading it if I don't like it. Life's short, time's precious, so why waste any of your time on something you are not enjoying if you don't have to be doing it? Unless the book is a class assignment in school and you know there'll be a test on it, there's no reason to trudge on through it if you are not enjoying it on some level (and heck, even if it is a class assignment, you can get a Cliff Notes for it or look it up on Wikipedia and get at least a snapshot of information about it that might give you enough to bullsh*t your way through any test questions, right?!).
Reading a book you are not enjoying seems so silly to me. If you find the story offensive, too dark, too light, too stupid...just not to your liking...you have the personal freedom to stop reading it. Put the book down and step away from it. Don't recommend it to your friends. Sell it at a garage sale, give it to a library or school, or toss it in the garbage if you like. There's no need to fret over it, complain to others about "having to read it," or carry on about how awful it is....just stop reading it and move on.
Life is short and time is precious, little ones, so don't waste it when you don't have to. Read what you love, what interests you, what teaches you, what brings you enjoyment, and to heck with the rest!