They are noisy, they stink, and they will drive deer out of the area.
The first two anyone with a brain can smell and hear, the last part comes from watching the deer that the ATV riders never see. One of the areas I have hunted is a large private hunting club. This is a closed environment where we can watch the effect of differing interaction between people, machines and wildlife. When the deer hear the ATV's coming, they leave.
A hunting partner and I have watched this many times. We set up just over the top of a big ridge and watch the open hillside below us. The road, more like a jeep trail comes up the ridge top just on the other side of the ridge. We use a raised blind that sets up above the brush. We can see the road and the deer, but the deer can not see the road, but they can hear the ATV's coming.
When watch the deer feeding along without a care in the world, then when the noise machines some along, they leave in a hurry. Mind you, they leave well in advance of the ATV riders ever getting close to them.
What I have seen with my own eyes clearly demonstrates that ATVs ruin the hunting for not only the riders, but all others in the area as well.
I believe there is a use for them in recovering game that has already been harvested, but there is no valid use for them as a hunting vehicle. In this state it is illegal to use an ATV off of an established road. I would even give folks a break on that law for recovering game, but the rest of the time they should be cited.
I hunt with horses, using my saddle horses and pack horses to get far away from noisy, lazy people. After Im miles inside of a Wilderness area safe from idiots, I tie up my horses and hunt on foot. I am a disabled Nam Vet. None of this is easy or without pain for me. The logistics of getting my animals and myself where I want to be takes time sweat and money. I know that if I am going to hunt as I want to, where I want to, that I must be willing to invest that time, energy, and money, or it will not happen