You need not use the whole posting, but definitely include enough so that a new reader can get a feeling for what you are saying. Remember how you felt when you first started reading NES, and use that feeling as a guide. Actually, I disagree with that statement. It is not that there aren't enough jobs, it's that there are too many scientists. You may find a way to express your ideas more clearly and concisely.
Few people read long posts.
The point of NES is to communicate, not to fight. This person might choose to post something the next day to the NES Digest or might send you a private email message. In turn, you might feel attacked in the new posting or in the email message. Perhaps the person misunderstood your idea. Or perhaps the person is an ass.