My attempt to boil the post down to a one sentence conclusion: being super into epistemic rationality is a very good thing, but it is not the only good thing.

i'm into epistemic rationality, but this all seems pretty much accurate and stuff

not sure what to conclude from having that reaction to this post.

I understand this to mean that the only value you see to non-brevity is its higher success at manipulation.

Is that in fact what you meant?

I suspect that the issue is not terseness, but rather not understanding and bridging the inferential distance between you and your audience. It's hard for me to say more without a specific example.

What does brevity offer you that makes it worthwhile, even when it impedes communication?

Predicting how communication will fail is generally Really Hard, but it's a good opportunity to refine your models of specific people and groups of people.

Well, you describe the problem as terseness.
If that's true, it suggests that one set of improvements might involve explaining your ideas more fully and providing more of your reasons for considering those ideas true and relevant and important.

Have you tried that?
If so, what has the result been?

I can see benefits to the principle of charity. It helps avoid flame wars, and from a Machiavellian point of view it's nice to close off the "what I actually meant was..." responses.

Some people are just bad at explaining their ideas correctly (too hasty, didn't reread themselves, not a high enough verbal SAT, foreign mother tongue, inferential distance, etc.), others are just bad at reading and understanding other's ideas correctly (too hasty, didn't read the whole argument before replying, glossed over that one word which changed the whole meaning of a sentence, etc.).

I've seen many poorly explained arguments which I could understand as true or at least pointing in interesting directions, which were summarily ignored or shot down by uncharitable readers.

naturalized!Cai

I'm not sure that using this notation is a good idea, given that at least some of the readers unfamiliar with it are likely to initially parse it as "naturalized not-Cai". Even I did for a brief moment, because I was parsing the writing using my logic!brain rather than my fanfiction!brain.

Most of your post is not arguments against curing death.

People being risk-averse has nothing to do with anti-aging research and everything to do with individuals not wanting to die...which has always been true (and becomes more true as life expectancy rises and the "average life" becomes more valuable). The same is true for "we should risk more lives for science".

I agree that people adapt OK to death, but I think you're poking a strawman; the reason death is bad is because it kills you, not because it makes your friends sad.

I think "death increases diversity" is a good argument. On the other hand, most people who present that argument are thrilled that life expectancy has increased to ~70 from ~30 in ancient history. Why stop at 70?

short response is "yeah, sure, sorta ... but only if you're a stupid group. we can do better."

edit: http://lesswrong.com/lw/jop/a_defense_of_senexism_deathism/akk3 is the longer version of this response