Keep in mind that your stack size in comparison to your opponent's is what will be driving your heads up strategy. Whether you are the leader or trailing you have different considerations and the value of your hand is relative to your stack in a preflop situation.
More importantly though, is the distribution of playable hands. On their website, Pokerroom continuously tabulates how many times you will get dealt a certain hand in holdem. This is an actual game count over the last 500,000 hands dealt on their website. So its hard to argue with these realities.
In a sense, this is what poker is all about. Havent you noticed that the players who can manage their emotions at the table are often the ones with the most success? When was the last time you saw Howard Lederer, Dan Harrington or Phil Gordon chastise somebody for any reason at the table?
6 seated tournaments also attract more reckless and care-free players looking for some sort of quick fix. They want to see action and will often get it in the form of getting kicked out early, or doubling up, further exposing you to more hands, and subsequently - quality hands. Just as you expect to see early all-in, and out exits in 9 seated tournaments, there are too in 6 seated! Apparantly a short table isnt fast enough for a lot of players!
To pull this strategy off, you essentially have to encourage your opponents lack of emotional control to the surface of his game, and especially when playing against you. You may think this inherently involves being aggressive with assertive pre and post flop betting. In many cases that may be true, but there is also opportunity for training your opponent by while acting passively.