I fail to see how men having only recently gotten the vote is a good argument against women getting the vote.
You neglected to include a good argument in favor of slavery.
If you look at my earlier post, and my examples in this post, you'll see that "altruistic deception" is when you present something that is false and unworkable in order to motivate people to do work that you hope will contribute to a real solution. Your objection amounts to saying that we can't say that anything is false, or even that one X is more false than another X.
Let's test your idea that "There are no good arguments for X" is simply how having a successful social taboo against X feels from inside:
"There are no good arguments for the phlogiston theory of chemistry" is simply how having a successful social taboo against the phlogiston theory of chemistry feels from inside.
"There are no good arguments for Ptolemaic astronomy" is simply how having a successful social taboo against Ptolemaic astronomy feels from inside.
"There are no good arguments for Aristotelian physics" is simply how having a successful social taboo against Aristotelian physics feels from inside.
Marxism is less able to make correct predictions, and more thoroughly empirically refuted, than any of those theories. It is a false theory. It is a not-even-wrong theory. If you ask a Marxist to predict whether a corn blight will make the price of corn go up or down, he can only say, "Markets are a tool of the bourgeois, and their prices are commodity fetishization." Marx deliberately removed the concept of market price from the Marxist ontology, so Marxists can't be tempted to make quantitative predictions and be proven wrong.
Christianity, my other example, is also bad at making predictions. I object to your implication that we cannot say that the theory of Christianity is less probable than the theory of evolution.
You neglected to include a good argument in favor of slavery.
Some people aren't intelligent enough/don't have high enough time preferences to function in modern society. Thus you either need to have them under the control of a master, or you wind up having to put them on the public dole and institutionalize the many of them anyway.
I've said before that social reform often seems to require lying. Only one-sided narratives offering simple solutions motivate humans to act, so reformers manufacture one-sided narratives such as we find in Marxism or radical feminism, which inspire action through indignation. Suppose you tell someone, "Here's an important problem, but it's difficult and complicated. If we do X and Y, then after five years, I think we'd have a 40% chance of causing a 15% reduction in symptoms." They'd probably think they had something better to do.
But the examples I used in that previous post were all arguably bad social reforms: Christianity, Russian communism, and Cuban communism.
The argument that people need to be deceived into social reform assumes either that they're stupid, or that there's some game-theoretic reason why social reform that's very worthwhile to society as a whole isn't worthwhile to any individual in society.
Is that true? Or are people correct and justified in not making sudden changes until there's a clear problem and a clear solution to it?
Examples, I think, of good social reform, were the abolition of slavery and the civil rights movement of the 1960s. Those movements didn't require wholesale lying and sleight-of-hand, because they could make valid and true one-sided arguments. It's hard to come up with a good counter-argument to "plantation slavery is bad". Even women's suffrage and Prohibition didn't require lying.
If you're backing a cause which doesn't inspire the action you think it deserves, and you find yourself twisting the truth a bit for dramatic effect, how strong evidence is that that your cause is less worthy than you think it is? Can you give examples where you would go ahead and twist the truth anyway?
For example, if you want to build an asteroid defense system for Earth, and the numbers say that the odds of it being needed in any given human generation are 0.0001%, it might not ever be worth it to any "purely selfish" human to pay the taxes to build that system. I'm ruling that example out, because it is really about the questions of how to discount the future and how to value future human lives. That's a known problem which this angle provides no new insight into.
If you want people to cooperate to reduce risk from AI, or to cure aging, but hardly anyone seems to care, would that fact affect your judgement of the task's true value to most people?
Essentially I'm asking whether you believe in the free market of ideas, in which the effort people put into different tasks is the real measure of their value, or whether you think we need some good-old Marxist centralized planning of values. Answer carefully, because I don't think you can both support the manipulation of public opinion wrt social issues or existential threats (because the public is too stupid to know what it should value), and still believe the free market can solve economic problems (because people are smart enough to know what they value).
A consequence of this observation is that we should expect Marxists, who believe the free market doesn't work, to lie much more often than capitalists, who think it does. Empirically, however, Democrats seem to lie much less than Republicans (see, e.g., a recent NY Times report on PolitiFact checking of the Presidential candidates), even though Republicans have much more faith in the free market.