KA,
The black bear is king of the jungle in Canada and Canadians don't even hunt bears for the most part. Mainly us Americans are hunting them and they just don't really fear man as Canadians see them all of the time while picking blueberries and no harm comes to the bear except from Americans. Canadian hunts are over bait only(for the most part) as there is nothing but thick bush and no visibility for spot and stalk hunting. The problem with a bear bait treestand is that it is setup and shooting lanes are cleared for that one position. You hunt that stand regardless of the wind direction and generally you have no option as the guide is not going to move you to another stand so you can always have the wind in your favor. The bears will usually scent the hunter IMO, he weighs the odds of you hurting him, and his hunger either overcomes his concern, or he hits the bait in the dark when you are not there.