Here in PA I can all but guarantee you the answer for most guys will be: Pressure and tresspassers.

It's such a pain in the butt, and so much stress to do your homework on public land or even private land, and to think you are in the right spot only to have someone bumble through at any point in the day and ruin your valuable time in the woods (especially since we can't hunt on Sundays)
And then on Private land you are always worrying about who is crossing the posted signs.

It's no fun to have your first thought each hunt be: "Well who is gonna screw this up today?"