Ahhh...the equation is incomplete. One of the variables is missing!

Bear spray also protects the bear.

Many if not most 'aggressive encounters' are surprise ones. That is, the hiker and the bear come into sudden and unintentional close contact. Sometimes it's a turn in the trail, sometimes it's stumbling upon a food cache, often it's a cub on one side and mama on the other. The point, here, is that the encounters aren't the result of an intentionally aggressive bear...seldom are the encounters the result of predatory actions (talking griz and black bear here).

None the less, very often when a bear mauls a hiker that bear faces two alternatives; relocation or euthanization. Not always...but it's common. If bear spray can deter an attack to the point where the hiker is unharmed that bear has a much better chance to live another day.

Bear spray works. Bear spray has prevented potential human injury. Bear spray can spare the life of the bear.

Not bad for 12+ oz.