Because dispassionate logic and reason lead to the best ideas.

For an example of what a devolution into appeals to emotion and base notions looks like, turn on Fox News or MSNBC during the evening and witness the demagogues screaming straight at your amygdala and hippocampus. The current cycle degradation of discourse has opened the door to "fake news" and other very real problems. In this case, the bogeyman is real.

What seems to be happening is that many intellectuals use dispassionate logic and reason to come up with good ideas, then refuse to use emotion in pitching these ideas. The ideas then get drowned out by the likes of Fox News and MSNBC peddling much less poorly thought out ideas.

If they did something else, they might be more persuasive, but would they still be rationalists?

Because we like to establish whether the ideas are good before trying to push them into the 'competition in the human mindshare'.

YIMBYs have already done that for themselves, and are now in the advocacy phase.

Sure, but there's a ton of different groups that have already 'established for themselves' that they're right, and are in 'advocacy phrase'.

Every group has people who advocate for the group beliefs in emotional, close-minded ways. Groups that have accurate beliefs will also have people who argue more dispassionately.

If you see a discourse dominated almost exclusively by tribal back-patting, it should put their beliefs in question.

This article is specifically considering the question: are YIMBY ideas good? Why might they not be?

I think they must think it elevates their discourse, as if appealing to emotion at all sullies them. While there is a reassuring sobriety to cold, rational thought, in itself it often doesn't motivate me to care. It's only really effective in preaching to the choir because they've chosen to hobble themselves by using only a third of the tools available to rhetoric. There are ways to rationally appeal to people's sense of ethics and to the full range of human emotions without descending into demagoguery.

If your goal is to convince other people of what you believe, all of those sound useful.

If your goal is to be convince if you're right, and be convinced if you're aren't, they become less so.

> It's only really effective in preaching to the choir because they've chosen to hobble themselves by using only a third of the tools available to rhetoric.

There are multiple audiences and many will reject emotional appeals out of hand. Certainly if you oppose New Urbanism, a guy ranting about how you're a racist is unlikely to change your mind.

> Why do supposed “rationalists” insist on trying to advocate everything through dispassionate, logical discourse?

They generally don't; reacting negatively, as here, to what is seen as a particularly egregious example of emotional manipulation without accompanying substantive argument isn't the same as insisting on all promotion being purely rational, and very few “rstionalists” take the extreme position you describe.

Still, they do tend to object to egregious examples because the nature of emotional manipulation is that once you recognize it directed at yourself, it naturally produces a strong negative emotional reaction and a reactive deepening of skepticism (the nature of such manipulation is that it is most likely to be noticed, even by sophisticated information consumers, when deployed in favor of a cause the listener is already skeptical of) of the substantive justification of the party deploying it.

> Do they have zero understanding of human psychology and sociological group dynamics?

It seems that, aside from the strawman problem, the question you ask demonstrates exactly the problem you complain of.

There's a place for emotional appeals and there's a place for rational consideration of arguments. One does not preclude the other.

because shouting louder doesn't make you right.

It makes people listen, though. Which I would presume is important if you are good at being right.

but being shouty and emotional isn't conditional on being right. In fact, being right is infamously hard to establish, assuming "rightness" is something you can even measure for the question at hand. So going for shouty means you're going to be heard, but you're no more likely to be right. The rationalist approach is to optimise for "rightness", or to be "less wrong" you could say. The problem is that the niche of people who take ideas from the community and market them to the wider world remains largely unfilled, especially compared to more-shouty-but-less-concerned-about-right political factions.