This whole issue has been discussed in detail elsewhere — it involves a saber-rattling Dan Simmons piece about a time traveler, stop me if you've heard this one before — but here's a perspective that's worth noting. (The Simmons piece itself is not even worth taking apart — other people did a better job of that after they stopped laughing contemptuously.)The point is simple: Life's too short to throw money at people you have contempt for.
Limited lifespan divided by number of books it's possible to consume due to vagaries of money and mortality equals I am not buying your books if you behave like a fuckmuppet in public.
There's a threshold you can set for how much you are willing to be offended by an author before you spend money on them. It sounds actually more like a formula with a couple of variables: time since publication, personal distance between you and the author, nature of the offense. It varies between people.
I know I have my own version of this, and I'm not ashamed of it. In fact, I think at this point it's basic human decency to not feel complicit with people you can't help but see as scumbags.
Por ejemplo. I have spent money on exactly two books by Louis-Ferdinand Céline, Journey to the End of the Night and Death on the Installment Plan. And that's all I'm ever going to buy. From what I've seen those two give you more or less everything you could possibly want of the man in all of his misanthropic insufferability. I found out after reading those two that Céline was responsible for a number of anti-Semitic pamphlets written slightly WWII. No, I could not find it within myself to excuse such behavior with some silly post hoc fluff like, "Well, it's okay because he probably just hated everyone equally in the end". Especially not after I had nearly been duped by the Holocaust-denial crew into swallowing their brand of (anti-Semitic) slop.
The same thing happened to a lesser extent with William Burroughs, although my disenchantment with him as an artist (he really did end up a one-trick pony) was the bigger motivator there.
People who enjoy a certain person's artistic input often find a way to condition themselves to ignore the person as a person. Edgar Winter once complained about this: once when he was hospitalized for something or other, he noted that it was one of the few times in his adult like when people didn't treat him like a jukebox. Hey, Edgar, you know that tune, the one that goes — ? Yeah, buddy, I know it, and I'm not going to sing it for you; sing it yourself.
Neil Gaiman recently protested this entitlement mentality when it manifested as thinking of a particular author as your employee. The author, if he works for anyone, works for himself — and his publisher and editor, and then his fans. If only because that's the way most of the business is set up.
Now, one of the other advantages of treating the person like a jukebox — or vending machine, or what have you — is that you can selectively disregard that person's moral failings. Yes, I know that Pablo Picasso was never called an asshole (even though, according to at least one of his biographers, he richly deserved it), and that Wagner alienated pretty much everyone he knew by being a grasping scumbag — but, hey, Guernica! And Lohengrin! And the thing is, a good deal of the time, that sort of argument gets plenty of mileage because it's not like Picasso or Wagner screwed you over personally.
On a long enough timeline, the grievance rate for everyone drops to zero.
The problem is that for people who are still alive and still producing, there's a non-trivial chance that we might get to know the person slightly better than casually. In fact, at this point, it's almost unavoidable.
I know from personal experience that I've had a couple of unpleasant whammies like this. Someone I admired as a creator — and thought I knew decently well as a person — turned out to hold views and opinions that just seemed so far out of phase with anything else they did or expressed that I scarcely knew how to react.
It's sort of like having the nice man on the bus next to you chat with you about the weather, and then between words he opens his briefcase and dumps a live snake in your lap. And, worse, he can't for the life of him figure out why you're freaking out and screaming and running up the aisle.
So what's the threshold for such things? It varies. Obviously, it makes no sense to cut yourself off from genuinely good work because of some petty disagreement with the creator — but what classifies as "petty" is going to vary wildly between people. If someone thought the Gulf War was not an inherently bad idea, that's one thing. The subject is at least something that can be contained within the realms of civil debate, especially if he shows that he's willing to examine his position. But if he thinks the sooner we bomb Country X the better, then I have that many less words to share with him about — well, anything.
I imagine that Dan Simmons sincerely feels the West is in danger (never mind that most of the people he sees as The Enemy are too busy trying to blow each other up first), and felt he was doing his duty speaking his mind by writing that story. Or maybe he wanted to take the ambivalence felt by contemplating such things and write about that. Fine with me: he's well within his rights to fall flat on his face.
And I'm well within my right to step over him on the way to hear someone else more worth my time.