Abstracts and general principles are all well and good, but give me a concrete example.
There are several reasons I like to avoid concrete examples (not that I always do, but I've gotten better at it than I used to be).
The tactical reasons, so to speak, take into account the direct effects of using concrete examples. In general terms, the discussion gets stuck in concrete. Is that what he really meant? Wouldn't this be a more charitable interpretation? What's the full relevant context in which to read that? Didn't I do the same thing, or worse? People tend to respond to the thing that is easiest to respond to (qv the Law of the Stupidest Argument), and concrete examples are usually easier to respond to than general principles.
Moreover, strategically speaking, I don't much care about concrete examples. Whether or not this particular person acted in this particular manner in this particular instance, acting in that manner is something we can talk about, and possibly benefit from talking about. Introducing a concrete (rather than hypothetical) example bears a real risk of introducing a sin against justice (particularly rash judgment or detraction), and it's usually an unnecessary risk.
On the down side, writing in generalities runs the risk of coyness, as though those in the know will put two and two together and see who I have in mind. That's a failure on my part to write clearly enough. If I don't show my work frankly, from concrete example through general principle, I shouldn't leave hints or clues for people to guess at.
There's also the risk of describing a phenomenon that doesn't actually occur in the real world, or at least that doesn't occur nearly as often as or to the extent that I think. But if I weren't willing to risk being an idiot, I wouldn't blog.
More seriously, and what I suspect Dan may have had in mind, is that, without a concrete example, it can be hard for others to know what I'm really getting at, and therefore whether I'm right about it. Abstractions that aren't understood in the concrete may be easy to reason with, but they aren't always easy to reason about.