The first 2 pages of 50 Shades of Grey were pretty offensive from a writer's perspective. I don't know about the rest of the book.
I have only never been "offended" by a book or movie, per se. I do find some characters or stories to be stupid or silly, or oddly out of character or disrespectful of canon, which I find is more of an insult to the intelligence of the viewer than "offensive". Like when Commander Tumblr Post decided to kamikaze a starship into an enemy ship and completely bends all previous canon about Hyperdrive travel over a table. But that wasn't "offensive" it was just "functionally retarded", or rather the writers were. So I don't find plot contrivances to be "offensive" but I do feel sometimes, a lot of times, the writer can insult the viewer and that's arguably worse IMO.
Context matters. I can't think of many subjects that would always offend me no matter what, it depends how the author is depicting the subject. For example, depicting rape wouldn't offend in itself, but if it seemed like the author was trying to glamorise the scene or excuse the attacker, that would.
Okay, I'm going to be pedantic here. Offended has a specific meaning, which is to be angry or hurt at a perceived insult. So, unless somebody is insulting me in writing, or I believe they are, I won't be 'offended' by what I read. I may be annoyed if I think the author is wrong, or if the book is poorly written or seems to be a diatribe for or against something. I may hate the book and chuck it in the bin after four pages, or it may make me furious for many different reasons—but 'offended?' I don't remember ever being offended by a book. I think people are starting to use 'offended by' as a catch-all term for being 'not happy with.' And I'm not happy with that.
Perhaps an author not being himself? I don't know everyone seems to be offended by things nowadays. I don't know if it's the internet or creating collective bubbles of thought but one opinion shouldn't have so much power that it needs to be snuffed out like a light. I get bristly … but offended? - maybe, I don't know. Offensive means the author is being deliberating insulting. How can you clearly ascribe that motive to every thought process? I'm sure there's some authors out there deliberately trying to offend and perhaps even the book I couldn't finish on my banned books list. But I was more sickened then offended.
I'm not sure about this layer of "deliberate" that people are adding to the meaning of the word. The first definition on good ol' Google is "causing someone to feel deeply hurt, upset, or angry." (I think this is from Oxford). M-W seems to allude toward deliberateness with "making attack", but doesn't clearly specify the "deliberate" part; Dictionary.com says "causing resentful displeasure; highly irritating, angering, or annoying"... Anyway, certainly no clear requirement for a deliberate element.
Swords, knifes, cannons, missiles, guns, tactical maneuvers that involve striking the first blow or taking it to the enemy. That sort of thing.
