From the comments:
As to the question of obnoxiousness, of course it’s obnoxious, which is to say nothing more than ‘polite society considers it obnoxious’, and for quite the same reason as it’s considered obnoxious to point out that life is wholly meaningless, ends with finality and that anyone who can of free conscious murder a stranger (and get away with it) for a hundred dollars but doesn’t do so is a fool with no mind of his own.
These are anti-social truths and therefore rude to mention in public. This isn’t to say that I don’t love you for saying them….
There are myths, and there are myths. I do for example think that ‘free will’ simply understood is a myth. In fact, people of many persuasions, whether they be religious or irreligious, also concur on this point. But prattling on about this is fruitless, and there’s a strong consensus that there are no returns on discussing the issue outside of narrow circles of highly intelligent and philosophically oriented sets. Arguments about ethics, and ‘rationality,’ and mental states require some subtly and a threshold of self-aware sentience which most of the human race is unfortunately incapable of.
I think foreign policy is different. This is not some deep existential issue, and nor is dispute without potential fruit. There is no overwhelming consensus about why, or if, we should support Israel, or oppose Israel, or not give much thought to the conflict between the Jewish state and the Arabs who claim it as their own. Yes, there are good and solid majorities in the United States and Europe, which fall in opposing campus. But there is still a fair amount of dispute where getting to the root of the difference of opinion may be a socially useful strategy.
My own attitudes toward American foreign policy are determined primarily by American interests (more precisely, my weak opinions are informed by my rather thin base of facts, which I input into a rough intuitive cost/benefit calculation which is calibrated by my own norms). Others argue that idealism drives their preferences in this domain; e.g., abstractions like democracy or liberty. As an empirical matter I think this idealism is just a rhetorical game in most cases (with the pro and anti-Israel sides engaging in a bidding war where many of the principals don’t even value the underlying currency of human rights nearly as much as the prices on the table would imply). In the interests of honesty, and not wasting time in signalling dynamics, I do attempt to get to the root of the matter by asking obnoxious questions if an opinion from my direction is demanded (the nature of the Israeli-Arab conflict are such that the principals either do not believe that you are uninterested, or, express anger and disgust if you admit a lack of interest).
There are certainly broad swaths of life where disputation and critical rationalism are overrated. I would never engage the typical dullard on the street as to the feasibility of a compatibilist position on free will. There is no game there to be had. On the other hand the dullard may have some inchoate stances on policy issues, and even maintain a marginal grasp on the various moving parts so that one can engage in the game of critical rationalism. Our tax dollars and time are on the line after all.