When evaluating any new item of technology, I always look at it from the perspective of how it impacts fair chase. Does it give an unfair advantage to the hunter? On the one hand, a lot of people say the scent loc stuff doesn't work, that it's just a hoax. But if it does work, if it actually does take away the animal's ability to smell the hunter, that's stacking the deck too much in the hunter's favor, IMO.
The same could be said for camouflage, of course. However, to animal eyes that don't see color, camo may not be a big advantage to the hunter. Deer, for example, may see camo as well as they see blaze orange, or plaid or whatever. In addition, regardless of the pattern worn, hunter movement is another visual cue that the hunted still has to use to their advantage.