The part about managers thinking less of you because you do not negotiate is completely true. Everybody wants an awesome negotiator under them. Just like if you solve P=NP on the white board on the interview will mark you as the wizard, negotiating will mark you, right from the interview, as someone who fights for what he wants, and will fight for what the project/team/company wants.
I upvoted you but I'm not so sure its the negotiation skills that they'll admire as much as the self confidence in your own market value. Sort of "This guy is used to getting paid really well, he must be really good."
