While I understand that this is an effective strategy, I don't understand what makes people choose not to respond at all rather than just saying "I'm not interested."
A possibility I'm considering is that I have an abnormally large desire for explicit closure. This also fits with my enjoyment of (or at least lack of being bothered by) anvilicious political points and technical digressions in science fiction.
Regarding your desire for explicit closure: I don't personally feel that explicit closure is actually possible in most cases. I will give you my personal "case studies" to help illustrate my thought process, since I seem to be the kind of person you don't understand.
I had a friend who was flakey and unreliable. I stopped contacting and responding to him after we agreed to meet somewhere and he never showed up, and gave no explanation. My thought process, insofar as I explicitly reasoned it out, was: The emotional cost (and "status"...
The other day, someone did something I didn't expect. It was something many people have done before; something that I thought of as very normal, but that I in no way understood and had not predicted.
As I said, this had happened many time before, so I wrote it off as "me not understanding people" or "people are weird" for a second, like I usually do, before realizing that "bad at" really means "lacking basic knowledge", which I had never realized before.
And then I thought "I should ask someone who is different from me why people do that, and eventually someone will have an answer."
But many people will have many more questions like this. So, what have you observed people doing time and time again, but never understood? Or something that you only understood after a long time or asking someone about it?
And can Less Wrong tell us, not necessarily why (I for one can make up evolutionary psychology fairy tales all day if I want) but what conscious thought process occurs behind these events?