I am a big fan of my bird being well manned to anything that might distract from hunting in the field and anything that might stress it at home or on the way to the field. Having said that I use the hood a great deal too and it is not to be underestimated as an aid to desensitizing a bird to stressful stimulus.
Where the hood is very effective in this process is that you can tightly control the amount of stimulus the hawk is exposed to down to the second. Rather than just bulling through until the bird becomes oblivious after having endured much stress, it can be phased in gently anytime it becomes too much on goes the hood and the bird gets break. used correctly the hood is actually a kindness to a wild hawk. the goal in training and maintaining a raptor into your hunting partner is to do so in a subtle and minimally stressful manner. A well fitted hood used well is very much your friend in this and a hawk should accept the hood without issue if done right.
There is a reason the hood is still used in falconry after a couple of thousand years and that is because it works, as they say "if it aint broke then dont fix it".