I don't think that sitting out in order to gain a place or two is really a respectful tactic. However, I've also learned that poker is sometimes much more that just playing the cards that you're dealt, so as they say, all's fair in ..........
I would say that I don't respect thouse who star sitting out 20 persons left to money, but I've done this no once myself when there is 3 places to hit the money and it's worth trying after several hours of tourney. However if ur short stacked u r to be aware of blinds being capable of devouring ur all money, so keep it in mind if u want to stay alive and go deeper in tourney to get more money. Good luck and more chips in order not to sit out often