Phil Munro writes:

It is really hard to follow a lot of posts these days from people who
do not include at least part of the posts they are replying to.

My news reader does not make it easy for me to find those posts. When
I've marked posts as "read", they do not show again -- without some
effort. And the idea of news group postings is to be able to scan as
quickly as possible.

It is normal, expected, and helpful for follow-up postings to include
enough of the previous thread to give explanation of the topic. I am
posting this only to help those who are not (yet) aware of what they
are doing. Thanks for reading. --Phil

A lot of these people are on Google Groups where they see
whole threads.

The rest are just clueless.

There's a page on Google where you can ask them to implement
quoting as default behavior. It's a simple form to fill
out.