Can you explain why you recommend trimming these messages before
replying?
(It wasn't my recommendation, but I do have some sympathy with it.)
For those of us on the digest version of the list, it's a bummer if
you don't. (I'd also characterize it as lazy and sloppy writing not
to trim the post to the specific contents to which you are replying,
but I recognize opinions may differ on this.)
Moreover, I disagree that the low cost of a resource is a good reason
for wasting it. (There may indeed by additional reasons that make it
so, but not by itself.)
It should not be too difficult, if you believe that certain content or
references are significant to your reply, to include only those of
pertinence.