One thing is for certain... you MUST bluff while playing NLHE. You absolutely HAVE to.
The question is... how often do you do it?
I guess that is determined by how the game is being played. How tight or loose are the other players? Who are you playing heads up against during that hand? Are there any action or scare cards? My main concern is trying to determine if another player is actually talented enough to know NOT to call in certain situations. Donks will call any bet, at any time during the hand. Do not try to bluff a donk, they will play their pocket 6s like the nuts until the end, and will end up catching trips on the river... even if the flop does come out A-K-J.
A bluff is most certainly necessary, the question is, how often is it part of your game?
I can eliminate myself from tournaments sometimes because I think EVERYONE is on a bluff or has the nuts a lot of the times. Paranoia, maybe? When I get into my own zone, I go far in tournaments, whether it be live or online. Time to buckle down and play some poker.