An example of the benefits of examples: Eli Tyre once told me you know you have understood the point someone was trying to make if you can give them a better example of their point than the one they already had. I am not often able to do this in practice, but the general act of paraphrasing things and including examples has been very beneficial for me. One of my favorite questions to ask myself and others is "for example?"
It's always been a bit of a mystery to me why examples are so hard to generate. Once I thought my own struggle to get a handful of good examples together was good evidence my thesis was weak, but I'm less sure of that now.
Even when examples do present themselves they are never "quite right"; there are so often other factors in the outcome, beyond your simply toy model, that it would require much handwaving and disclaimer to persuade relevance.
And yet, as you say, they're butter to argument's bread.
Examples, analogies and lingo all make posts easier to understand. So then, I want to encourage people to write more comments like:
I see comments like this sometimes, but much less frequently than I would like. And I suspect that readers often have thoughts like "Z could be a good term for that", but don't think it's worth saying. I think these comments are almost always worth saying.
Crowdsourcing
Examples, analogies and lingo seem like such great things to crowdsource. Even if the post author is intimately familiar with the post's content, I would expect 100 readers who are vaguely familiar with the content to do a better job of coming up with examples, analogies and lingo than the single post author. They're just the sorts of things that benefit a lot from a diversity of viewpoints, it seems to me.
Non-expert explanation
Let's say I'm wrong in the above section and the reality is that the post author is better than the crowd at coming up with good examples, analogies and phrases. Even so, sometimes the "good" example from the post author doesn't make much sense to a particular reader whereas a "mediocre" example from a commenter is what makes it click.
Scott Alexander does a great job of talking about this concept in his post Non-Expert Explanation.
Post authors don't always do a good job
Coming up with good examples, analogies and lingo is hard! There's a lot of times when I have an idea in my mind that I want to write about but I get stuck because I have trouble coming up with good examples, analogies or lingo. There are also times when I post it anyway, knowing that I haven't done a good job with those things.
I doubt I'm alone. I doubt that every time someone clicks "Submit" on a post that they think they've done as good a job as possible in the examples, analogies and lingo they've used.