I object to trees in general and in the fairway in particular because they are simply no fun. From a bunker, or rough, or any land form, the player always has a chance to hit a heroic shot and get back in the hole. These hazards provide options, and options equal freedom, and freedom is the meaning of life.
Trees are like water hazards, you hit them and you're dead - period. That sucks.
The Scots have had St. Andrews Old Course for five hundred years and look at how many trees they have planted. That should tell us something.