Fear is the lowest form of motivation that can be used for self-aware beings. Unfortunately, it also is one of the most often used in religion - starting with fear of God and eternal punishment, visualized most vividly with the image of a fiery pit. Thankfully, Mormon theology removes the most blatant fear-mongering aspects of traditional Christianity, but there are plenty of people even within Mormonism who use fear as the primary motivational technique.
Why is that so - especially with regard to good, caring people?
1) Some people just aren't "people persons" - and fear is the easy way to deal with people when you are uncomfortable doing so intimately. (For that matter, "because I'm the leader and I said so," fits that category, as well.)
2) Some people have never had "love" modeled as a form of motivation. Even when someone "knows better", it's really hard to implement a model they have never seen modeled actively - especially during their formative years. That's one reason why those who been abused tend to abuse so much - the lack of a different response mechanism even as they hate the fact that they do what they abhorred in the abuser.
Recognizing that such approaches (motivation through fear) in the Church usually are the result of either "dealing with people" weakness or being the only model that a person knows helps tremendously to be charitable AND not succumb to the tactics.