I don't finish every book I start. I don't think anybody should.
I mean, my to be read pile, at the moment, consists of 172 books. If I finished every book I began, I'd have a helluva lot of reading to do.
I do finish most books I read. It takes a lot for me to put a book down - I have to really not be into it, or not be in the mood for it, or be forced to return it because it's a library book. But when I do realize that I'm forcing myself to read something, I put it aside.
Why?
Well, as I said, my to be read pile consists of 172 books. I don't own 172 books. I own 172 books that I have to read. This doesn't include the books I own that I like rereading every now and then (another 200) or the books that are on my reading wish list (about 300). I need to weed through them somehow, and when I read them, sometimes I discard them to the side. I don't see a problem with this. Not every book is for everybody at any given moment. There's no reason to suffer through it.
I don't always blog about books I don't finish. Sometimes I do. Sometimes I don't. It depends on what I have to say about them. Matched, for instance - I had some great things to say about it and I wanted to state my reasons as to why I couldn't finish a book that's been so popular. On the other hand, I couldn't get though Kindred when I started reading my ARC of it and had to put it aside. Even though I was supposed to write a review of it for the tour, I didn't - though I had been in the mood for it when I started, I ended up not liking it at all, but I still think it's going to find a decent audience with fans of Twilight and Hush, Hush.
The moral of this post:
You don't have to finish every book you read, especially when there are other books you'd rather be reading or other things that you have to do. You're not going to like every book (if you do, I applaud you). And if you're me, you can talk about it or not talk about it depending on if you have something to say.
But I don't think there's a problem if you don't finish.
Side note: Matched coverlust.