top posting?

Just out of curiousity, I see comments like this all the time:

> (*please* stop top-posting).

I've been participating in newsgroups since UUCP days, and I've never
encountered a group before that encouraged bottom posting. Bottom posting
has traditionally been considered rude -- it forces readers to scroll,
often through pages and pages of text, to see a few lines of original
material.

The most efficient strategy, one that respects other members' time, is to
briefly summarize your point at the TOP of a posting, then to *briefly*
quote only the relevant parts of the post to which you are replying, and
bottom-post after the quoted text. That lets your reader quickly see if
it's relevant or not, and move on to the next post.

Contributors in these newsgroups seem to think it's OK to quote five pages
of someone else's response, then add one or two sentences at the bottom ...
it's just laziness that forces readers to wade through the same stuff over
and over in each thread.

How did the Postgres newsgroups get started with this "only bottom post"
idea?

(I'm not trying to start a flame war, just genuinely curious.)

Craig